deps: update googleapis/java-cloud-bom digest to 6626f91 (#3147)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| googleapis/java-cloud-bom | action | digest | `a98202d` -> `6626f91` |

---

> [!WARNING]
> Some dependencies could not be looked up. Check the Dependency
Dashboard for more information.

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

This PR was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/googleapis/sdk-platform-java).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOC41OS4yIiwidXBkYXRlZEluVmVyIjoiMzguNTkuMiIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOltdfQ==-->

Author: renovate-bot

.github/workflows/ci.yaml

@@ -330,7 +330,7 @@ jobs:
       run: |
         mvn install -B -ntp -DskipTests -Dclirr.skip -Dcheckstyle.skip
     - name: Validate gapic-generator-java-bom
-      uses: googleapis/java-cloud-bom/tests/validate-bom@a98202d674b36364d7963945095e9826bbe57833
+      uses: googleapis/java-cloud-bom/tests/validate-bom@6626f91d2ea122ba19d15e33c8a6bc21aebe5177
       with:
         bom-path: gapic-generator-java-bom/pom.xml