Update Microsoft.Extensions.AI dependencies (#1755)

Copilot-Session: 268e897b-5571-4b1e-b840-41697fe52dd2

Author: jeffhandley

Directory.Packages.props

@@ -1,10 +1,10 @@
 <Project>
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
-    <System8Version>8.0.22</System8Version>
-    <System9Version>9.0.11</System9Version>
+    <System8Version>8.0.29</System8Version>
+    <System9Version>9.0.18</System9Version>
     <System10Version>10.0.10</System10Version>
-    <MicrosoftExtensionsVersion>10.5.2</MicrosoftExtensionsVersion>
+    <MicrosoftExtensionsVersion>10.8.3</MicrosoftExtensionsVersion>
   </PropertyGroup>
 
   <!-- Product dependencies shared -->