[Backport release_3_8] Github Action PHPUnit Matrix update

[rldhont]

Backport #5170
Authored by: @rldhont

[3liz-bot]

The backport to release_3_7 failed:

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

stderr

To https://github.com/3liz/lizmap-web-client.git
 ! [remote rejected]     backport-5173-to-release_3_7 -> backport-5173-to-release_3_7 (refusing to allow a Personal Access Token to create or update workflow `.github/workflows/tests.yml` without `workflow` scope)
error: failed to push some refs to 'https://github.com/3liz/lizmap-web-client.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-release_3_7 release_3_7
# Navigate to the new working tree
cd .worktrees/backport-release_3_7
# Create a new branch
git switch --create backport-5173-to-release_3_7
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 6ccf10ff8598460a3be0fce48512314c4889f520
# Push it to GitHub
git push --set-upstream origin backport-5173-to-release_3_7
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release_3_7

Then, create a pull request where the base branch is release_3_7 and the compare/head branch is backport-5173-to-release_3_7.