Fix CI go.sum path for caching

Author: Panonim

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
           path: |
             ~/go/pkg/mod
             ~/.cache/go-build
-          key: ${{ runner.os }}-go-${{ hashFiles('backend/go.sum') }}
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
           restore-keys: |
             ${{ runner.os }}-go-