Bump actions/upload-artifact from 6 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/code-quality-and-tests.yml

@@ -64,7 +64,7 @@ jobs:
     # Step 11: Upload test results as artifacts (optional)
     - name: Upload test results
       if: always()
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: test-results-${{ matrix.python-version }}
         path: |

.github/workflows/test-main-features.yml

@@ -69,7 +69,7 @@ jobs:
         poetry run python tests/test_main_features.py
 
     - name: Upload test results
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       if: always()
       with:
         name: test-results