[BUGFIX] Remove ".rst" endings from menues

[linawolf]

Sphinx allows this while it is not in the standard, the guides can currently not interpret it correctly

releases: main, 12.4, 11.5

[github-actions]

The backport to 11.5 failed:

The process '/usr/bin/git' failed with exit code 1

stderr

error: could not apply 00dcd21... [BUGFIX] Remove ".rst" endings from menues
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".

stdout

Auto-merging Documentation/Extensions/Index.rst
CONFLICT (content): Merge conflict in Documentation/Extensions/Index.rst
CONFLICT (modify/delete): Documentation/Localization.ru_RU/Extensions/Index.rst deleted in HEAD and modified in 00dcd21 ([BUGFIX] Remove ".rst" endings from menues).  Version 00dcd21 ([BUGFIX] Remove ".rst" endings from menues) of Documentation/Localization.ru_RU/Extensions/Index.rst left in tree.
CONFLICT (modify/delete): Documentation/Localization.ru_RU/Setup/Index.rst deleted in HEAD and modified in 00dcd21 ([BUGFIX] Remove ".rst" endings from menues).  Version 00dcd21 ([BUGFIX] Remove ".rst" endings from menues) of Documentation/Localization.ru_RU/Setup/Index.rst left in tree.
CONFLICT (modify/delete): Documentation/Localization.ru_RU/Troubleshooting/Index.rst deleted in HEAD and modified in 00dcd21 ([BUGFIX] Remove ".rst" endings from menues).  Version 00dcd21 ([BUGFIX] Remove ".rst" endings from menues) of Documentation/Localization.ru_RU/Troubleshooting/Index.rst left in tree.

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-11.5 11.5
# Navigate to the new working tree
cd .worktrees/backport-11.5
# Create a new branch
git switch --create backport-321-to-11.5
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 00dcd21ae8ed205df52a27105ba1235f6eee7ef8
# Push it to GitHub
git push --set-upstream origin backport-321-to-11.5
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-11.5

Then, create a pull request where the base branch is 11.5 and the compare/head branch is backport-321-to-11.5.