ci(Go): add Go 1.21 setup to test job

.github/workflows/go.yml

@@ -24,11 +24,15 @@ jobs:
       run: go build -v ./...
 
   test:
-    needs: build
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
 
+    - name: Set up Go
+      uses: actions/setup-go@v4
+      with:
+        go-version: '1.21'
+
     - name: Test
       run: go test -v -cover ./...