Update image name to perfsonar-testpoint-arm64

Author: jkafader-esnet

.github/workflows/dockerhub-arm64-push.yml

@@ -29,7 +29,7 @@ jobs:
       uses: docker/setup-buildx-action@v3
 
     - name: Build the Docker image for arm64 platforms
-      run: docker buildx build . --file Dockerfile --tag my-image-name:arm64:$(date +%s) --platform linux/arm/v7
+      run: docker buildx build . --file Dockerfile --tag perfsonar-testpoint-arm64:$(date +%s) --platform linux/arm/v7
 
     - name: Publish to Docker Hub
       uses: docker/build-push-action@v1