Tag and Push frontend dashboard image only on Push event

Workflow dispatch event is triggered on changes to server image.
This should build the notebook server image as it uses the server image.

But frontend is Javascript nodejs based image and is unrelated to the server.
Check this review comment:
e-mission#125 (comment)

.github/workflows/image_build_push.yml

@@ -105,8 +105,8 @@ jobs:
           echo "Workflow_dispatch: New server image built and pushed, Updating image tag in .env"
           echo "SERVER_IMAGE_TAG=$DOCKER_TAG_FROM_WORKFLOW_DISPATCH" > .env
         # else
-        #   echo "Push event: Restoring latest server image tag in .env"
-        #   echo "SERVER_IMAGE_TAG=$DOCKER_TAG_FROM_PUSH" > .env
+          echo "Push event: Restoring latest server image tag in .env"
+          # echo "SERVER_IMAGE_TAG=$DOCKER_TAG_FROM_PUSH" > .env
         fi
 
     - name: Add, Commit, Push changes to .env file
@@ -143,12 +143,16 @@ jobs:
 
     - name: rename docker images
       run: |
-        docker image tag em-pub-dash-dev/frontend:latest $DOCKER_USER/${GITHUB_REPOSITORY#*/}:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
+        if [ "${{ github.event_name }}" == "push" ]; then
+          docker image tag em-pub-dash-dev/frontend:latest $DOCKER_USER/${GITHUB_REPOSITORY#*/}:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
+        fi
         docker image tag em-pub-dash-dev/viz-scripts:latest $DOCKER_USER/${GITHUB_REPOSITORY#*/}_notebook:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
 
     - name: push docker images
       run: |
-        docker push $DOCKER_USER/${GITHUB_REPOSITORY#*/}:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
+        if [ "${{ github.event_name }}" == "push" ]; then
+          docker push $DOCKER_USER/${GITHUB_REPOSITORY#*/}:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
+        fi
         docker push $DOCKER_USER/${GITHUB_REPOSITORY#*/}_notebook:${GITHUB_REF##*/}_${{ steps.date.outputs.date }}
    
     - name: Create a text file