revert: chore: update librarian to v0.25.0 (googleapis#17670)

This reverts commit d93bce4.

Author: codyoss

librarian.yaml

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 language: python
-version: v0.25.0
+version: v0.22.0
 repo: googleapis/google-cloud-python
 sources:
   googleapis: