Run GitHub Actions build on all branches

[geographika]

Run build on all branches, but only deploy on branch-8-0.

[github-actions[bot]]

The backport to branch-8-0 failed:

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

stderr

``` To https://github.com/MapServer/MapServer-documentation.git ! [remote rejected] backport-882-to-branch-8-0 -> backport-882-to-branch-8-0 (refusing to allow a GitHub App to create or update workflow `.github/workflows/build.yml` without `workflows` permission) error: failed to push some refs to 'https://github.com/MapServer/MapServer-documentation.git' ```

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-882-to-branch-8-0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 8285618f8d43c656669253df79f16df2310204e3
# Push it to GitHub
git push --set-upstream origin backport-882-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-882-to-branch-8-0.