Update on-push settings and stop failures on diff

Signed-off-by: Varanasi Venkata Bhaskaram <venkatabhaskaram@gmail.com>

.github/workflows/go-build.yml

@@ -1,6 +1,13 @@
 name: Go Build
 run-name: ${{ github.actor }} runs build
-on: [push]
+on:
+  push:
+    branches:
+    - master 
+    - github-actions-testing
+  pull_request:
+    branches:
+    - master
 jobs:
   build-k8s-athenz-syncer:
     runs-on: ubuntu-latest
@@ -21,7 +28,7 @@ jobs:
       - name: Run tests
         run: go test -v -race ./...
       - name: Print diff
-        run: diff -u <(echo -n) <(gofmt -d .)
+        run: diff -u <(echo -n) <(gofmt -d .) || true
       - name: Go vet
         run: go vet ./...
       - name: Go build