[AppConfig] Update API Compat version (#38628)

The focus of these changes is to update the API Compat target after the 1.2.1 release.

Author: jsquire

Diff for: sdk/appconfiguration/Azure.Data.AppConfiguration/src/Azure.Data.AppConfiguration.csproj

@@ -5,7 +5,7 @@
     <AssemblyTitle>Microsoft Azure.Data.AppConfiguration client library</AssemblyTitle>
     <Version>1.3.0-beta.3</Version>
     <!--The ApiCompatVersion is managed automatically and should not generally be modified manually.-->
-    <ApiCompatVersion>1.2.0</ApiCompatVersion>
+    <ApiCompatVersion>1.2.1</ApiCompatVersion>
     <PackageTags>Microsoft Azure Application Configuration;Data;AppConfig;$(PackageCommonTags)</PackageTags>
     <TargetFrameworks>$(RequiredTargetFrameworks)</TargetFrameworks>
     <NoWarn>$(NoWarn);3021;</NoWarn>