Update codecov-actions version

Author: f-allian

.github/workflows/ci-tests.yaml

@@ -36,8 +36,7 @@ jobs:
       run: |
         pytest --cov=causal_testing --cov-report=xml
     - name: "Upload coverage to Codecov"
-      uses: codecov/codecov-action@v2
+      uses: codecov/codecov-action@v5
       with:
         fail_ci_if_error: true
         token: ${{ secrets.CODECOV_TOKEN }}
-        version: "v0.1.15"