[CP #1541 > support/v5.12] [doc] downgrade Sphinx to < 7.3

[eclipse-ecal-bot]

Cherry-pick failed

Cherry-picked PR #1541 to branch support/v5.12.
The cherry-pick has failed.

The following files have caused conflicts:

doc/requirements.txt

Resolving

Please resolve conflicts manually. You can use this PR and branch to your convenience.

git fetch origin
git checkout -b local/cherry-pick/09f56b3/support/v5.12 origin/support/v5.12
git branch -u origin/cherry-pick/09f56b3/support/v5.12
git cherry-pick f1988303e58c5e2e77497614d616b44e5703817f..09f56b32b32370c2809b7c6921a85fa8b7c7a400

# Resolve conflicts and use
#     git cherry-pick --continue
# until all conflicts are resolved.

git push -f origin HEAD:cherry-pick/09f56b3/support/v5.12

After resolving all conflicts, rebase-merge this PR.