fix copy&paste error in test build action

Author: wollomatic

.github/workflows/docker-image-testing.yaml

@@ -56,7 +56,7 @@ jobs:
             docker.io/wollomatic/socket-proxy:testing-${{ github.sha }}
 
       - name: Sign Docker Hub image
-        run: cosign sign --yes --recursive --key env://COSIGN_PRIVATE_KEY docker.io/wollomatic/socket-proxy:${{ steps.get_tag.outputs.VERSION }}@${{ steps.push-dockerhub.outputs.digest }}
+        run: cosign sign --yes --recursive --key env://COSIGN_PRIVATE_KEY docker.io/wollomatic/socket-proxy:testing-${{ github.sha }}@${{ steps.push-dockerhub.outputs.digest }}
         env:
           COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
           COSIGN_PASSWORD: ${{ secrets.COSIGN_PASSWORD }}
@@ -74,7 +74,7 @@ jobs:
             ghcr.io/wollomatic/socket-proxy:testing-${{ github.sha }}
 
       - name: Sign GHCR image
-        run: cosign sign --yes --recursive --key env://COSIGN_PRIVATE_KEY ghcr.io/wollomatic/socket-proxy:${{ steps.get_tag.outputs.VERSION }}@${{ steps.push-ghcr.outputs.digest }}
+        run: cosign sign --yes --recursive --key env://COSIGN_PRIVATE_KEY ghcr.io/wollomatic/socket-proxy:testing-${{ github.sha }}@${{ steps.push-ghcr.outputs.digest }}
         env:
           COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
           COSIGN_PASSWORD: ${{ secrets.COSIGN_PASSWORD }}