Update errorprone to sync with Guava (#7110)

Author: elharo

google-cloud-clients/pom.xml

@@ -341,7 +341,7 @@
       <dependency>
         <groupId>com.google.errorprone</groupId>
         <artifactId>error_prone_annotations</artifactId>
-        <version>2.3.3</version>
+        <version>2.3.4</version>
       </dependency>
       <dependency>
         <groupId>org.easymock</groupId>