feat(git): get branch commit without cloning (#7130)

lib/manager/npm/post-update/index.ts

lib/platform/azure/index.spec.ts

lib/platform/azure/index.ts

lib/platform/bitbucket-server/index.spec.ts

lib/platform/bitbucket-server/index.ts

lib/platform/bitbucket/index.spec.ts

lib/platform/bitbucket/index.ts

lib/platform/gitea/index.spec.ts

lib/platform/gitea/index.ts

lib/platform/github/index.spec.ts

lib/platform/github/index.ts

lib/platform/gitlab/index.spec.ts

lib/platform/gitlab/index.ts

lib/util/git/__snapshots__/index.spec.ts.snap

lib/util/git/index.spec.ts

lib/util/git/index.ts

lib/workers/branch/index.spec.ts

lib/workers/branch/index.ts

lib/workers/branch/lock-files/index.spec.ts

lib/workers/branch/reuse.spec.ts