Bump go to 1.19 in github actions unit/integration tests.

Author: MirahImage

.github/workflows/pr.yml

@@ -15,6 +15,10 @@ jobs:
     runs-on: ubuntu-latest
     container: us.gcr.io/cf-rabbitmq-for-k8s-bunny/rabbitmq-for-kubernetes-ci
     steps:
+    - name: Install Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ env.GO_VERSION }}
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
     - name: Unit tests