message: tests: registry: revert readonly permission after running tests.
  Fixes
diff: @@ -2003,25 +2003,28 @@ fn readonly_registry_still_works() {
  p.cargo("generate-lockfile").run();
  p.cargo("fetch --locked").run();
  - chmod_readonly(&paths::home());
  + chmod_readonly(&paths::home(), true);
  p.cargo("build").run();
  + // make sure we un-readonly the files afterwards so "cargo clean" can remove them (#6934)
  + chmod_readonly(&paths::home(), false);
  - fn chmod_readonly(path: &Path) {
  +
  + fn chmod_readonly(path: &Path, readonly: bool) {
  for entry in t!(path.read_dir()) {
  let entry = t!(entry);
  let path = entry.path();
  if t!(entry.file_type()).is_dir() {
  - chmod_readonly(&path);
  + chmod_readonly(&path, readonly);
  } else {
  - set_readonly(&path);
  + set_readonly(&path, readonly);
  }
  }
  - set_readonly(path);
  + set_readonly(path, readonly);
  }
  - fn set_readonly(path: &Path) {
  + fn set_readonly(path: &Path, readonly: bool) {
  let mut perms = t!(path.metadata()).permissions();
  - perms.set_readonly(true);
  + perms.set_readonly(readonly);
  t!(fs::set_permissions(path, perms));
  }
  }
  