fix: [#34] added condition to prevent images pulling

.github/workflows/docker-registry.yml

@@ -37,22 +37,27 @@ jobs:
       - name: Create registry backup directory
         run: mkdir -p ${{ env.DOCKERFILE_CONTEXT }}/backup-registry
       - name: Pull images data and prepare context directory
+        if: startsWith(github.ref, 'refs/tags/')
         shell: bash
         run: |
           #!/bin/bash
+
           docker run -d \
             -p 5000:5000 \
             --name mcvs-registry-tmp \
             registry:${{ env.REGISTRY_VERSION }}
 
+          # disable tls for local tmp registry
           regctl registry set --tls disabled ${{ env.REGISTRY_LOCAL }}
 
+          # import image with manifest list
           regctl \
             image \
             copy --digest-tags \
             ${{ env.REGISTRY_REMOTE }}/${{ env.IMAGE_MANIFEST_LIST }} \
             ${{ env.REGISTRY_LOCAL }}/${{ env.IMAGE_MANIFEST_LIST }}
 
+          # import image with single manifest
           regctl \
             image \
             copy --digest-tags \