Fix pip cache ordering: move checkout first, use setup-python built-in cache (#71)

* Initial plan

* Fix checkout order and use setup-python built-in pip cache

Co-authored-by: MMathisLab <28102185+MMathisLab@users.noreply.github.com>
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* Upgrade actions/checkout and setup-python to v6

Update .github/workflows/python-package.yml to use actions/checkout@v6 and actions/setup-python@v6. Keeps the workflow up-to-date with no functional changes to Python version or caching.

* Cache only pyproject.toml in CI

Update GitHub Actions workflow to use pyproject.toml as the sole cache-dependency-path for pip, removing requirements.txt, setup.cfg, and setup.py to avoid unnecessary cache invalidation. Add a clarifying comment and clean up trailing whitespace in the workflow file.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: MMathisLab <28102185+MMathisLab@users.noreply.github.com>
Co-authored-by: Cyril Achard <cyril.achard@epfl.ch>

Author: 3 people

.github/workflows/python-package.yml

@@ -20,21 +20,18 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+
       - name: Setup Python
         id: setup-python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.x'
-
-      - name: Cache dependencies
-        id: pip-cache
-        uses: actions/cache@v4
-        with:
-          path: ~/.cache/pip
-          key: ${{ runner.os }}-pip-${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('pyproject.toml', 'requirements.txt', 'setup.cfg', 'setup.py') }}
-          restore-keys: |
-            ${{ runner.os }}-pip-${{ steps.setup-python.outputs.python-version }}-
-            ${{ runner.os }}-pip-
+          cache: 'pip'
+          # we only use pyproject.toml for dependencies
+          cache-dependency-path: |
+            pyproject.toml
 
       - name: Install Qt/OpenGL runtime deps (Ubuntu)
         run: |
@@ -45,7 +42,7 @@ jobs:
             libopengl0 \
             libxkbcommon-x11-0 \
             libxcb-cursor0
-            
+
       - name: Install dependencies
         run: |
           pip install --upgrade pip
@@ -54,9 +51,6 @@ jobs:
           pip install build
           pip install twine
 
-      - name: Checkout code
-        uses: actions/checkout@v4
-
       - name: Build and publish to PyPI
         if: ${{ github.event_name == 'push' }}
         env: