Fix pre-commit autoupdate workflow by forking one of the hooks

[alexdewar]

Description

One of the hooks we are using appears to be unmaintained ([cffconvert]) and there is unfortunately an issue that means that pre-commit autoupdate falls over when it hits this repo. There doesn't appear to be any way to get the GitHub Action we are using to ignore this repo either.

We could just drop the hook, but I think it's useful, so instead I forked it here and made a new release: https://github.com/EnergySystemsModellingLab/cffconvert

Note that I didn't change any code; just making the release is enough to fix the problem.

We can always change back to using the upstream version if someone else takes over maintainership (though the last release was in 2021...).

Type of change

• Bug fix (non-breaking change to fix an issue)
• New feature (non-breaking change to add functionality)
• Refactoring (non-breaking, non-functional change to improve maintainability)
• Optimization (non-breaking change to speed up the code)
• Breaking change (whatever its nature)
• Documentation (improve or add documentation)

Key checklist

• All tests pass: $ cargo test
• The documentation builds and looks OK: $ cargo doc
• Update release notes for the latest release if this PR adds a new feature or fixes a bug
  present in the previous release

Further checks

• Code is commented, particularly in hard-to-understand areas
• Tests added that prove fix is effective or that feature works

[Copilot]

Pull request overview

Updates the pre-commit configuration to use a maintained fork of cffconvert, addressing failures in the pre-commit autoupdate workflow caused by the upstream repo being unmaintained.

Changes:

• Switch validate-cff hook source repo from citation-file-format/cffconvert to EnergySystemsModellingLab/cffconvert.
• Update the pinned rev from a commit SHA to the fork’s 2.1.0 release tag.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.50%. Comparing base (28dee31) to head (3e63945).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1163   +/-   ##
=======================================
  Coverage   87.50%   87.50%           
=======================================
  Files          57       57           
  Lines        7675     7675           
  Branches     7675     7675           
=======================================
  Hits         6716     6716           
  Misses        657      657           
  Partials      302      302           

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[tsmbland]

Annoying, but I'm okay with it