Bump the actions group across 1 directory with 2 updates

Bumps the actions group with 2 updates in the /.github/workflows directory: [actions/setup-python](https://github.com/actions/setup-python) and [actions/upload-artifact](https://github.com/actions/upload-artifact).


Updates `actions/setup-python` from 5 to 6
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v5...v6)

Updates `actions/upload-artifact` from 4 to 5
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/upload-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/publish-to-test-pypi.yml

@@ -13,7 +13,7 @@ jobs:
       steps:
         - uses: actions/checkout@v5
         - name: Set up Python
-          uses: actions/setup-python@v5
+          uses: actions/setup-python@v6
           with:
             python-version: "3.x"
 

.github/workflows/pytest.yml

@@ -20,7 +20,7 @@ jobs:
     steps:
     - uses: actions/checkout@v5
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
@@ -30,7 +30,7 @@ jobs:
     - name: Test with pytest
       run: |
         pytest --mpl --mpl-results-path=results --mpl-generate-summary=html
-    - uses: actions/upload-artifact@v4
+    - uses: actions/upload-artifact@v5
       if: failure()
       with:
         name: pytest-${{ matrix.python-version }}-results