Revert codecov action (raviqqe#55)

Author: raviqqe

.github/workflows/test.yaml

@@ -23,6 +23,6 @@ jobs:
       - uses: actions/checkout@v4
       - uses: Swatinem/rust-cache@v2
       - run: tools/coverage.sh
-      - uses: codecov/codecov-action@v4
+      - uses: codecov/codecov-action@v3
         with:
           files: lcov.info