deps: use error_prone_annotation via shared deps (#1049)

Declaring the error_prone_annotation version fails consistency check in downstream repository:

googleapis/java-logging-logback#829 (comment)

Reading #1009, it shouldn't need the independent version declared here.

Author: suztomo

google-cloud-logging/pom.xml

@@ -98,7 +98,6 @@
     <dependency>
       <groupId>com.google.errorprone</groupId>
       <artifactId>error_prone_annotations</artifactId>
-      <version>2.15.0</version>
     </dependency>
 
     <!-- Test dependencies -->