Update build-and-test.yaml

.gitea/workflows/build-and-test.yaml

@@ -23,7 +23,7 @@ jobs:
           go-version: "1.24.5"
 
       - name: Tidy and Vendor
-        run: go mod tidy && go mod vendor
+        run: cd backend && go mod tidy && go mod vendor
 
       - name: build
         run: go build -v ./backend/...