fix(skopeo): use official image

mentioned in commit 2c05b33a

mentioned in merge request to-be-continuous/samples/maven-on-openshift!96 (merged)

mentioned in merge request to-be-continuous/samples/maven-on-gcloud!151 (merged)

mentioned in merge request to-be-continuous/samples/maven-on-kubernetes!152 (merged)

mentioned in merge request to-be-continuous/samples/maven-library!51 (merged)

mentioned in merge request d3269/tbc-cicd-for-java!18