chore: updating OwlBot.lock sha256 value to the latest (#9257)

Updating OwlBot.lock sha256 value to the latest

Author: yoshi-code-bot

.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-java:latest
-  digest: sha256:5df8b62e8da534f7604daef347698f6701e34b3f61713712a3384ac88fc32088
+  digest: sha256:bf5639d265d70f6137d57d42ae781a6f4e26d4085ff4e018e71350480f9b3996
   # created: 2023-01-20T00:00:00.000000000Z