Bump codecov/codecov-action from 3 to 4 (#177)

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

Author: dependabot[bot]

.github/workflows/unit_test.yaml

@@ -28,6 +28,6 @@ jobs:
           make test
 
       - name: Upload to Codecov
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         with:
           file: ./coverage.txt