Bump error_prone_core from 2.19.1 to 2.20.0

Bumps [error_prone_core](https://github.com/google/error-prone) from 2.19.1 to 2.20.0.
- [Release notes](https://github.com/google/error-prone/releases)
- [Commits](google/error-prone@v2.19.1...v2.20.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

pom.xml

@@ -150,7 +150,7 @@
               <path>
                 <groupId>com.google.errorprone</groupId>
                 <artifactId>error_prone_core</artifactId>
-                <version>2.19.1</version>
+                <version>2.20.0</version>
               </path>
             </annotationProcessorPaths>
           </configuration>