Bump error_prone_annotations from 2.7.1 to 2.8.1

Bumps [error_prone_annotations](https://github.com/google/error-prone) from 2.7.1 to 2.8.1.
- [Release notes](https://github.com/google/error-prone/releases)
- [Commits](google/error-prone@v2.7.1...v2.8.1)

---
updated-dependencies:
- dependency-name: com.google.errorprone:error_prone_annotations
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -91,7 +91,7 @@
     <jacoco-maven-plugin.version>0.8.7</jacoco-maven-plugin.version>
     <maven-pitest-plugin.version>1.6.7</maven-pitest-plugin.version>
     <pitest-junit5-plugin.version>0.14</pitest-junit5-plugin.version>
-    <error-prone.version>2.7.1</error-prone.version>
+    <error-prone.version>2.8.1</error-prone.version>
     <nullaway.version>0.9.1</nullaway.version>
     <revapi-maven-plugin.version>0.14.3</revapi-maven-plugin.version>
     <revapi-java.version>0.24.4</revapi-java.version>