Improve method of deriving repo name from pullspec

Theoretically, this works if the IMAGE reference contains a port number.

Co-authored-by: Adam Cmiel <[email protected]>

task/oci-copy/0.1/oci-copy.yaml

@@ -105,7 +105,7 @@ spec:
         echo "Extracting artifact_type"
         ARTIFACT_TYPE=$(cat "$(pwd)/source/$OCI_COPY_FILE" | yq '.artifact_type')
 
-        REPO=$(echo ${IMAGE} | awk -F ':' '{print $1}')
+        REPO=${IMAGE%:*}
         echo "Found that ${REPO} is the repository for ${IMAGE}"
 
         cat >artifact-manifest.json <<EOL