feat: keep multiple versions of github pages

[FrenchGithubUser]

When we started hosting our own version of the docs, we had to change the github workflow to build the docs to an org-approved one, which handled things differently. It was using the "deploy from github actions" method instead of "deploy from branch".

This PR adds what's necessary to keep all docs versions in this branch, which allows the version dropdown picker to work.

Adding/removing folders in this gh-pages branch allows to alter what's shown in the version picker.

[Copilot]

Pull request overview

Updates the documentation deployment workflow to preserve multiple published doc versions by deploying each build into a version-specific directory on the gh-pages branch, instead of uploading a single Pages artifact that replaces the whole site.

Changes:

• Switches from actions/configure-pages + actions/deploy-pages to a git-worktree-based push to gh-pages, updating only /$VERSION/.
• Changes workflow permissions to allow repository writes needed for pushing to gh-pages.
• Renames the docs job and adjusts comments/branch-to-version mapping text.

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.37%. Comparing base (be8156c) to head (cf0a121).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #255      +/-   ##
==========================================
- Coverage   80.38%   80.37%   -0.02%     
==========================================
  Files         501      501              
  Lines       72337    72337              
  Branches    10906    10906              
==========================================
- Hits        58148    58139       -9     
- Misses      10907    10913       +6     
- Partials     3282     3285       +3     

see 2 files with indirect coverage changes

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

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[jason-famedly]

Seems legit. Let's do it!