fix: use main

Author: thomasrockhu-codecov

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Run tests and collect coverage
         run: pytest --cov app
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@th/do-not-merge
+        uses: codecov/codecov-action@main
         with:
           fail_ci_if_error: true
           verbose: true