chore(deps): bump codecov-action to v6 (#57)

Bump codecov/codecov-action from v5 to v6.

Author: dependabot[bot]

.github/workflows/go.yml

@@ -80,7 +80,7 @@ jobs:
 
       - name: Upload coverage to Codecov
         if: matrix.os == 'ubuntu-latest'
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           file: ./coverage.txt
           flags: unittests