DOC: Remove section about deprecation notices

[david-cortes-intel]

Description

There is a section in the docs about deprecation notices, but this section has not been used for previous deprecations. Currently, the only thing it contains is the deprecation of macOS builds, which was a long time ago.

Since this sections is not being used and does not contain a log of previous deprecations, I think it's reasonable to remove it altogether.

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Checklist:

Completeness and readability

• I have updated the documentation to reflect the changes or created a separate PR with updates and provided its number in the description, if necessary.
• Git commit message contains an appropriate signed-off-by string (see CONTRIBUTING.md for details).
• I have resolved any merge conflicts that might occur with the base branch.

Testing

• I have run it locally and tested the changes extensively.
• All CI jobs are green or I have provided justification why they aren't.