Bump actions/upload-artifact from 4 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/docs.yml

@@ -84,7 +84,7 @@ jobs:
 
       - name: Upload documentation artifact
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: documentation
           path: docs/build/html/

.github/workflows/wheels.yml

@@ -378,7 +378,7 @@ jobs:
           output-dir: wheelhouse
           config-file: "{package}/pyproject.toml"
 
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v7
         with:
           name: cibw-wheels-cp${{ matrix.python }}-${{ matrix.platform_id }}
           path: wheelhouse/*.whl