peribolos: get full repo details lazily
peribolos: get full repo details lazily

Previously peribolos, with `--fix-repos` was enabled, called `GetRepo`
for all repos in an org. This is wasteful when those repos are not even
considered to be updated, so this was fixed to only get full repo
details when peribolos consider a specific configured repo for be
created or updated.

monopole/test-infra,monopole/test-infra,cblecker/test-infra,BenTheElder/test-infra,dims/test-infra,BenTheElder/test-infra,fejta/test-infra,ixdy/kubernetes-test-infra,michelle192837/test-infra,kubernetes/test-infra,BenTheElder/test-infra,dims/test-infra,jessfraz/test-infra,pwittrock/test-infra,jessfraz/test-infra,fejta/test-infra,cjwagner/test-infra,jessfraz/test-infra,brahmaroutu/test-infra,dims/test-infra,monopole/test-infra,monopole/test-infra,cblecker/test-infra,jessfraz/test-infra,cblecker/test-infra,cblecker/test-infra,michelle192837/test-infra,pwittrock/test-infra,dims/test-infra,michelle192837/test-infra,kubernetes/test-infra,jessfraz/test-infra,cjwagner/test-infra,brahmaroutu/test-infra,kubernetes/test-infra,kubernetes/test-infra,cjwagner/test-infra,michelle192837/test-infra,fejta/test-infra,cjwagner/test-infra,ixdy/kubernetes-test-infra,monopole/test-infra,monopole/test-infra,fejta/test-infra,pwittrock/test-infra,dims/test-infra,BenTheElder/test-infra,brahmaroutu/test-infra,ixdy/kubernetes-test-infra,BenTheElder/test-infra,brahmaroutu/test-infra,brahmaroutu/test-infra,BenTheElder/test-infra,kubernetes/test-infra,michelle192837/test-infra,cblecker/test-infra,brahmaroutu/test-infra,ixdy/kubernetes-test-infra,jessfraz/test-infra,dims/test-infra,kubernetes/test-infra,pwittrock/test-infra,fejta/test-infra,ixdy/kubernetes-test-infra,michelle192837/test-infra,cjwagner/test-infra,cjwagner/test-infra,cblecker/test-infra,fejta/test-infra,pwittrock/test-infra