fix(deps): update dependency com.google.protobuf:protobuf-bom to v3.21.6 (#1792)

[![Mend Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com) This PR contains the following updates: | Package | Change | Age | Adoption | Passing | Confidence | |---|---|---|---|---|---| | [com.google.protobuf:protobuf-bom](https://developers.google.com/protocol-buffers/) ([source](https://togithub.com/protocolbuffers/protobuf)) | `3.21.5` -> `3.21.6` | [![age](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-bom/3.21.6/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-bom/3.21.6/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-bom/3.21.6/compatibility-slim/3.21.5)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-bom/3.21.6/confidence-slim/3.21.5)](https://docs.renovatebot.com/merge-confidence/) | --- ### ⚠ Dependency Lookup Warnings ⚠ Warnings were logged while processing this repo. Please check the Dependency Dashboard for more information. --- ### Release Notes <details> <summary>protocolbuffers/protobuf</summary> ### [`v3.21.6`](https://togithub.com/protocolbuffers/protobuf/compare/v3.21.5...v3.21.6) [Compare Source](https://togithub.com/protocolbuffers/protobuf/compare/v3.21.5...v3.21.6) </details> --- ### 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, click this checkbox. --- This PR has been generated by [Mend Renovate](https://www.mend.io/free-developer-tools/renovate/). View repository job log [here](https://app.renovatebot.com/dashboard#github/googleapis/gax-java). <!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzMi4xOTQuNSIsInVwZGF0ZWRJblZlciI6IjMyLjE5OC4xIn0=-->

Author: renovate-bot

pom.xml

@@ -162,7 +162,7 @@
  <dependency>
  <groupId>com.google.protobuf</groupId>
  <artifactId>protobuf-bom</artifactId>
- <version>3.21.5</version>
+ <version>3.21.6</version>
  <type>pom</type>
  <scope>import</scope>
  </dependency>