Conform SignedDataVerifier & ChainVerifier to Sendable#94

StefanPrintezis wants to merge 1 commit intoapple:mainapple/app-store-server-library-swift:mainfrom

StefanPrintezis:sp/safe-concurrency-for-signed-data-verifierStefanPrintezis/app-store-server-library-swift:sp/safe-concurrency-for-signed-data-verifierCopy head branch name to clipboard