chore: upgrade weasyprint & replace python 3.9 with python 3.14

[dpinol]

Solves #107

• weasyprint==62.3 has a known vulnerability https://nvd.nist.gov/vuln/detail/CVE-2025-68616
• python 3.9 is end-of-life since 2025-10-31

[domWalters]

Hey,

Just tried to use Weasyprint 68.1 and I get this horrific mess:

Traceback (most recent call last):
  File "/path/to/project/.venv/bin/mkdocs", line 10, in <module>
    sys.exit(cli())
  File "/path/to/project/.venv/lib/python3.10/site-packages/click/core.py", line 1161, in __call__
    return self.main(*args, **kwargs)
  File "/path/to/project/.venv/lib/python3.10/site-packages/click/core.py", line 1082, in main
    rv = self.invoke(ctx)
  File "/path/to/project/.venv/lib/python3.10/site-packages/click/core.py", line 1697, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/path/to/project/.venv/lib/python3.10/site-packages/click/core.py", line 1443, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/path/to/project/.venv/lib/python3.10/site-packages/click/core.py", line 788, in invoke
    return __callback(*args, **kwargs)
  File "/path/to/project/.venv/lib/python3.10/site-packages/mkdocs/__main__.py", line 288, in build_command
    build.build(cfg, dirty=not clean)
  File "/path/to/project/.venv/lib/python3.10/site-packages/mkdocs/commands/build.py", line 347, in build
    config.plugins.on_post_build(config=config)
  File "/path/to/project/.venv/lib/python3.10/site-packages/mkdocs/plugins.py", line 602, in on_post_build
    return self.run_event('post_build', config=config)
  File "/path/to/project/.venv/lib/python3.10/site-packages/mkdocs/plugins.py", line 568, in run_event
    result = method(**kwargs)
  File "/path/to/project/src/mkdocs_to_pdf/plugin.py", line 134, in on_post_build
    self.generator.on_post_build(config, self.config['output_path'])
  File "/path/to/project/src/mkdocs_to_pdf/generator.py", line 176, in on_post_build
    render = html.render()
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/__init__.py", line 222, in render
    return Document._render(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/document.py", line 201, in _render
    [Page(page_box) for page_box in page_boxes],
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/document.py", line 201, in <listcomp>
    [Page(page_box) for page_box in page_boxes],
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/__init__.py", line 131, in layout_document
    pages = list(make_all_pages(context, root_box, html, pages))
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/page.py", line 1005, in make_all_pages
    page, resume_at = remake_page(i, context, root_box, html)
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/page.py", line 946, in remake_page
    page, resume_at, next_page = make_page(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/page.py", line 664, in make_page
    root_box, resume_at, next_page, _, _, _ = block_level_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 59, in block_level_layout
    return block_level_layout_switch(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 75, in block_level_layout_switch
    return block_box_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 126, in block_box_layout
    result = block_container_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 763, in block_container_layout
    next_page, new_children, new_max_lines) = _in_flow_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 557, in _in_flow_layout
    collapsing_through, max_lines) = block_level_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 59, in block_level_layout
    return block_level_layout_switch(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 75, in block_level_layout_switch
    return block_box_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 126, in block_box_layout
    result = block_container_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 763, in block_container_layout
    next_page, new_children, new_max_lines) = _in_flow_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 557, in _in_flow_layout
    collapsing_through, max_lines) = block_level_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 59, in block_level_layout
    return block_level_layout_switch(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 75, in block_level_layout_switch
    return block_box_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 126, in block_box_layout
    result = block_container_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 763, in block_container_layout
    next_page, new_children, new_max_lines) = _in_flow_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 557, in _in_flow_layout
    collapsing_through, max_lines) = block_level_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 59, in block_level_layout
    return block_level_layout_switch(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/block.py", line 86, in block_level_layout_switch
    result = grid_layout(
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/layout/grid.py", line 611, in grid_layout
    columns = _get_template_tracks(box.style['grid_template_columns'])
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/css/__init__.py", line 1222, in __missing__
    value = COMPUTER_FUNCTIONS[key](self, key, value)
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/css/computed_values.py", line 610, in grid_template
    return _track_size(style, name, values)
  File "/path/to/project/.venv/lib/python3.10/site-packages/weasyprint/css/computed_values.py", line 589, in _track_size
    elif value[0] == 'minmax()':
TypeError: 'FunctionBlock' object is not subscriptable

I tried main on weasyprint and I don't get this error. So I think I'll need to wait for weasyprint to make a new release.