Switch to Python MapScript with comments

[geographika]

As noted in MapServer/MapServer#6892 the Python MapScript uploaded to PyPI didn't contain the doxygen comments used to create the MapScript API docs.
I've uploaded a new version to test.pypi.org with comments so switching to this should resolve the missing MapScript docs (see current live docs with empty comments: https://mapserver.org/mapscript/mapscript-api/stub/mapscript.mapObj.html#mapscript.mapObj

The Travis script to generate docs (added in #610) from the main branch was commented out in 85716ce. This means it is currently not possible to review changes added to main at https://mapserver.github.io/MapServer-documentation/ before backporting to the live docs (or to review docs for an upcoming release).

I've readded the call to the script - I can debug and fix if there are issues with Travis and this script.

[jmckenna]

thanks @geographika

[github-actions]

The backport to branch-8-0 failed:

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

stderr

error: could not apply 65a65b92... Switch to Python MapScript with comments
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 .travis.yml
CONFLICT (content): Merge conflict in .travis.yml

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-branch-8-0 branch-8-0
# Navigate to the new working tree
cd .worktrees/backport-branch-8-0
# Create a new branch
git switch --create backport-817-to-branch-8-0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 65a65b92a6745b19bc6782f0c35830b6bf438d17
# Push it to GitHub
git push --set-upstream origin backport-817-to-branch-8-0
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-branch-8-0

Then, create a pull request where the base branch is branch-8-0 and the compare/head branch is backport-817-to-branch-8-0.

[geographika]

Thanks @jmckenna - MapScript docs now correctly displayed again on live: https://mapserver.org/mapscript/mapscript-api/stub/mapscript.mapObj.html#mapscript.mapObj