update codecov

.github/workflows/go.yml

@@ -28,4 +28,7 @@ jobs:
         run: go test -v -race -coverprofile=coverage.out -covermode=atomic ./...
 
       - name: Upload coverage reports to Codecov
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v4.0.1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          slug: mk6i/retro-aim-server