add buildkit support

Author: evshvarov

.github/workflows/build-push-gcr.yaml

@@ -50,7 +50,7 @@ jobs:
 
     - name: Build and Push image
       run: |
-        docker build -t ${GCR_LOCATION}/${PROJECT_ID}/${IMAGE_NAME}:${GITHUB_SHA} .
+        docker buildx build -t ${GCR_LOCATION}/${PROJECT_ID}/${IMAGE_NAME}:${GITHUB_SHA} .
         docker push ${GCR_LOCATION}/${PROJECT_ID}/${IMAGE_NAME}:${GITHUB_SHA}
 
     - name: Deploy to Cloud Run