fix: update build.yml

.gitea/workflows/build.yml

@@ -28,8 +28,10 @@ jobs:
 
       - name: Build Go application
         run: |
+          cd backend
           mkdir -p build
           go env -w GOPROXY=https://go.hub.ipao.vip,direct
+          go mod tidy
           CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o build/app .
 
       - name: Build final Docker image