[prone] Add `error-prone.picnic.tech` featuring `RedundantStringConversion`#2

Pankraz76 wants to merge 1 commit intomainPankraz76/spring-framework:mainfrom

unused-prone-RedundantStringConversion-UnusedMethodPankraz76/spring-framework:unused-prone-RedundantStringConversion-UnusedMethodCopy head branch name to clipboard