chore: add regex to match unmanaged dependency check (#1941) (#1630)

Source-Link: googleapis/synthtool@ca7a716
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-java:latest@sha256:cecae6152a85d55c932a64515643cf2e32a1f1b6e17503080eb07744b2177f28

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: gcf-owl-bot[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: sha256:1fb09a3eb66af09221da69087fd1b4d075bc7c79e508d0708f5dc0f842069da2
-# created: 2024-02-05T19:43:08.106031548Z
+  digest: sha256:cecae6152a85d55c932a64515643cf2e32a1f1b6e17503080eb07744b2177f28
+# created: 2024-03-25T17:31:37.187420732Z