Bot Framework DotNet SDK 4.21.0

Welcome to the September 2023 minor release of the Bot Framework SDK.

What's Changed

Teams

• Support Bot new invoke type: config by @yingduyingdu in #6632
• [Teams] Add support for meeting participants added/removed events by @ceciliaavila in #6677
• Implementation of Teams batch APIs by @ceciliaavila in #6655

Other

• Add WithAuthority to MSAL client application builder by @sw-joelmut in #6671
• Drop ADAL to unblock pipeline by @Danieladu in #6687
• Resolve concurrency issues in InterfaceConverter's ReadJson method by @ramfattah in #6681
• Use LRUCache in ExpressionParser for efficient memory usage by @ramfattah in #6667
• Upgrade ANTLR to version 4.11.1 in Microsoft.Bot.Builder.Parsers.LU project by @ceciliaavila in #6670
• Updated stray Microsoft.Rest.ClientRuntime dependency by @tracyboehrer in #6675
• #6673 - Fix of SNI auth not working in Cert based authentication by @mikeus-hanzlik in #6676
• Update JwtTokenExtractor.cs by @xieofxie in #6685
• Updated NuGet.Packaging by @tracyboehrer in #6652
• fix: cleanup streaming high-perf logs by @stevengum in #6650
• Explicitly adding 3.1 to test steps. by @tracyboehrer in #6666
• Microsoft.Rest.ClientRuntime from 2.3.21 to 2.3.24 by @tracyboehrer in #6662
• [#6642] Handle null content by @ceciliaavila in #6654
• [#6644] Remove BotFrameworkAdapter Obsolete annotation by @ceciliaavila in #6648
• Adding Microsoft SECURITY.MD by @microsoft-github-policy-service in #6639

New Contributors

• @microsoft-github-policy-service made their first contribution in #6639
• @mikeus-hanzlik made their first contribution in #6676

Full Changelog: 4.20.0...4.21.0