chore(deps): update plugin com.dorongold.task-tree to v2.1.1 (#1206)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| com.dorongold.task-tree | `2.1.0` -> `2.1.1` | [![age](https://badges.renovateapi.com/packages/maven/com.dorongold.task-tree/2.1.1/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.dorongold.task-tree/2.1.1/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.dorongold.task-tree/2.1.1/compatibility-slim/2.1.0)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.dorongold.task-tree/2.1.1/confidence-slim/2.1.0)](https://docs.renovatebot.com/merge-confidence/) |

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gax-java/build.gradle

@@ -5,7 +5,7 @@ plugins {
   id 'io.github.gradle-nexus.publish-plugin' version '1.1.0'
 
   id 'com.diffplug.eclipse.apt' version '3.40.0' apply false
-  id 'com.dorongold.task-tree' version '2.1.0' apply false
+  id 'com.dorongold.task-tree' version '2.1.1' apply false
   id 'com.github.johnrengelman.shadow' version '7.1.2' apply false
   id 'com.github.sherter.google-java-format' version '0.9' apply false