Bump codecov/codecov-action from 4 to 5 in the actions group (#32)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/tests.yml

@@ -81,7 +81,7 @@ jobs:
     - name: Run pytest
       run: pytest mne_gui_addons --cov-report=xml
     - name: Upload coverage stats to codecov
-      uses: codecov/codecov-action@v4
+      uses: codecov/codecov-action@v5
       with:
         token: ebcd818a-7a71-470d-b667-7cd9c3003c7d
       if: success() || failure()