gh-actions: upgrade codecov to v5

Author: mr-c

.github/workflows/ci-tests.yml

@@ -72,7 +72,7 @@ jobs:
 
       - name: Upload coverage to Codecov
         if: ${{ matrix.step == 'unit' }}
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v5
         with:
           fail_ci_if_error: true
         env: