fix: Revert "refactor: move branch cache files to util/cache" (#18667)

lib/util/cache/branch/index.ts

lib/util/git/behind-base-branch-cache.spec.ts

lib/util/git/behind-base-branch-cache.ts

lib/util/git/conflicts-cache.spec.ts

lib/util/git/conflicts-cache.ts

lib/util/git/index.spec.ts

lib/util/git/index.ts

lib/util/git/modified-cache.spec.ts

lib/util/git/modified-cache.ts

lib/util/git/parent-sha-cache.spec.ts

lib/util/git/parent-sha-cache.ts

lib/util/git/set-branch-commit.spec.ts

lib/util/git/set-branch-commit.ts

lib/workers/repository/cache.ts

lib/workers/repository/process/write.ts