registry-replacer: add ignore-repos option

[Prucek]

Add --ignore-repos flag to registry-replacer

Changes:

• Add --ignore-repos flag that accepts org/repo notation (can be passed multiple times)
• Skip processing for repos in the ignore list
• Add openshift/origin into the ignore list

The dockerfile-inputs feature will handle base image detection at build time, while registry-replacer will skip these repos in its periodic runs.

Related: Phase 2 of dockerfile-inputs rollout (registry-replacer deprecation) Needs: https://github.com/openshift/ci-tools/pull/4851