Disable github workflow steps for Pull Requests

.github/workflows/publish-docker.yml

@@ -31,7 +31,8 @@ jobs:
         uses: docker/setup-qemu-action@v1
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
-      - name: Login to DockerHub
+      - if: github.event_name != 'pull_request'
+        name: Login to DockerHub
         uses: docker/login-action@v1
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
@@ -41,5 +42,5 @@ jobs:
         with:
           context: .
           platforms: linux/amd64, linux/arm64
-          push: true
+          push: ${{ github.event_name != 'pull_request' }}
           tags: gravitl/netmaker:${{ env.TAG }}