updated dotnet version

Author: naseif

.github/workflows/dotnet.yml

@@ -4,7 +4,7 @@ on:
   push:
 
 env:
-  DOTNET_VERSION: "7.x.x" # The .NET SDK version to use
+  DOTNET_VERSION: "9.x.x" # The .NET SDK version to use
   SOLUTION_DIR: "VisualPairCoding"
   PROJECT: "./VisualPairCoding.AvaloniaUI/VisualPairCoding.AvaloniaUI.csproj"
   RELEASEPREFIX: "VisualPairCoding"