Update dependency com.google.errorprone:error_prone_core to v2.21.1

Author: renovate[bot]

pom.xml

@@ -63,7 +63,7 @@
         <mockito.version>5.4.0</mockito.version>
         <hamcrest.version>1.3</hamcrest.version>
         <maven-compiler-plugin.version>3.11.0</maven-compiler-plugin.version>
-        <errorprone.version>2.20.0</errorprone.version>
+        <errorprone.version>2.21.1</errorprone.version>
         <errorprone.javac.version>9+181-r4173-1</errorprone.javac.version>
 
         <sonar.projectKey>dropwizard_metrics</sonar.projectKey>