chore(deps): 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/build.yaml

@@ -65,7 +65,7 @@ jobs:
           echo "✓ Build artifacts verified: $wheel_count wheel(s), $tar_count source distribution(s)"
 
       - name: "Upload Build Artifacts"
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         if: contains(github.server_url, 'github.com')
         with:
           name: ${{ env.SDK_DIST_NAME }}

.github/workflows/test.yaml

@@ -38,7 +38,7 @@ jobs:
         run: uv run pytest -m "not integration" --cov=src/sap_cloud_sdk --cov-report=xml --cov-report=html --cov-report=term-missing
 
       - name: "Upload Coverage Report"
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         if: contains(github.server_url, 'github.com')
         with:
           name: coverage-report