[BUGFIX] Remove meta menu from subpage

[brotkrueml]

This avoids the warnings:

./Documentation/Concepts/Index.rst:74: WARNING: toctree contains reference to nonexisting document 'Concepts/Sitemap'
./Documentation/Concepts/Index.rst:74: WARNING: toctree contains reference to nonexisting document 'Concepts/genindex'

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 55b0f21... [BUGFIX] Remove meta menu from subpage
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

CONFLICT (modify/delete): Documentation/Localization.ru_RU/Concepts/Index.rst deleted in HEAD and modified in 55b0f21 ([BUGFIX] Remove meta menu from subpage).  Version 55b0f21 ([BUGFIX] Remove meta menu from subpage) of Documentation/Localization.ru_RU/Concepts/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-155-to-11.5
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 55b0f218c771009c38923600a5ccb56f865fc853
# Push it to GitHub
git push --set-upstream origin backport-155-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-155-to-11.5.

[github-actions]

The backport to 12.4 failed:

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

stderr

error: could not apply 55b0f21... [BUGFIX] Remove meta menu from subpage
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

CONFLICT (modify/delete): Documentation/Localization.ru_RU/Concepts/Index.rst deleted in HEAD and modified in 55b0f21 ([BUGFIX] Remove meta menu from subpage).  Version 55b0f21 ([BUGFIX] Remove meta menu from subpage) of Documentation/Localization.ru_RU/Concepts/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-12.4 12.4
# Navigate to the new working tree
cd .worktrees/backport-12.4
# Create a new branch
git switch --create backport-155-to-12.4
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 55b0f218c771009c38923600a5ccb56f865fc853
# Push it to GitHub
git push --set-upstream origin backport-155-to-12.4
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-12.4

Then, create a pull request where the base branch is 12.4 and the compare/head branch is backport-155-to-12.4.