Make auth provider token caches thread-safe (#1595)#1708

tarekgh wants to merge 2 commits into

modelcontextprotocol:mainmodelcontextprotocol/csharp-sdk:mainfrom

tarekgh:fix-thread-safe-auth-token-cachestarekgh/csharp-sdk:fix-thread-safe-auth-token-cachesCopy head branch name to clipboard