Update Roslyn package version in support doc

A new Roslyn 4.3.x package was released and the old package was unlisted. See https://www.nuget.org/packages/Microsoft.CodeAnalysis.Common/4.3.1

Author: JoeRobich

docs/extensibility/roslyn-version-support.md

@@ -23,7 +23,7 @@ As an example, to ensure that your custom analyzer works on all versions of Visu
 
 | Roslyn package version | Minimum supported Visual Studio version |
 | - | - |
-| 4.3.0 | Visual Studio 2022 version 17.3 |
+| 4.3.1 | Visual Studio 2022 version 17.3 |
 | 4.2.0 | Visual Studio 2022 version 17.2 |
 | 4.1.0 | Visual Studio 2022 version 17.1 |
 | 4.0.1 | Visual Studio 2022 RTM |