Updating example target.

Author: jsquire

examples/OpenAI.Examples.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
-    
+    <TargetFramework>net9.0</TargetFramework>
+
     <!-- CS1591 - Ignore XML doc comments on test types and members-->
     <NoWarn>$(NoWarn);CS1591;</NoWarn>