Bump the actions group with 2 updates (#278)

Bumps the actions group with 2 updates: [actions/download-artifact](https://github.com/actions/download-artifact) and [actions/upload-artifact](https://github.com/actions/upload-artifact).


Updates `actions/download-artifact` from 5 to 6
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@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/download-artifact
  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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/pypi-package.yml

@@ -48,7 +48,7 @@ jobs:
 
     steps:
       - name: Download packages built by build-and-inspect-python-package
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           name: Packages
           path: dist

.github/workflows/tests.yml

@@ -45,7 +45,7 @@ jobs:
         run: |
           cat ./logs/docsbuild.log
       - name: Upload
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: doc-html-${{ matrix.branch }}
           path: www/