Fix main workflow

Checkout for `go test` was done with the wrong reference

Author: damyan

.github/workflows/pipeline.yaml

@@ -51,6 +51,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Setup golang
         uses: actions/setup-go@v3
@@ -70,6 +72,9 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+
       - name: Complie manifests
         uses: azure/k8s-bake@v2
         with:
@@ -84,6 +89,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Login to Container Registry
         uses: docker/login-action@v2