Update CI configuration

- Merge LaTeX and Coverage into the main CI file
- Only run tests when a relevant file changes
- Update ``actions/checkout``
- Set ``-Werror`` only on pytest steps
- Reduce verbosity on the documentation workflow

doc/tutorial/deploying.rst

@@ -192,7 +192,7 @@ contents:
        permissions:
          contents: write
        steps:
-       - uses: actions/checkout@v3
+       - uses: actions/checkout@v4
        - name: Build HTML
          uses: ammaraskar/sphinx-action@master
        - name: Upload artifacts