deps: Bump the microsoft-packages group with 2 updates (#1848)

Bumps Microsoft.Agents.AI.GitHub.Copilot from 1.17.0 to 1.19.0
Bumps Microsoft.Extensions.AI from 10.8.3 to 10.9.0

---
updated-dependencies:
- dependency-name: Microsoft.Agents.AI.GitHub.Copilot
  dependency-version: 1.19.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: microsoft-packages
- dependency-name: Microsoft.Extensions.AI
  dependency-version: 10.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: microsoft-packages
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/Squad.Agents.AI/Squad.Agents.AI.csproj

@@ -35,7 +35,7 @@
   </ItemGroup>
   <ItemGroup>
     <InternalsVisibleTo Include="Squad.Agents.AI.Tests" />
-    <PackageReference Include="Microsoft.Agents.AI.GitHub.Copilot" Version="1.17.0" />
+    <PackageReference Include="Microsoft.Agents.AI.GitHub.Copilot" Version="1.19.0" />
     <!--
       Direct reference to GitHub.Copilot.SDK so its build/ targets fire during our build.
       Without this, the SDK's MSBuild download/copy targets only flow to projects with a
@@ -52,7 +52,7 @@
       project (see Directory.Build.props for the full explanation).
     -->
     <PackageReference Include="GitHub.Copilot.SDK" Version="$(SquadCopilotSdkVersion)" />
-    <PackageReference Include="Microsoft.Extensions.AI" Version="10.8.3" />
+    <PackageReference Include="Microsoft.Extensions.AI" Version="10.9.0" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="10.0.11" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.11" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.11" />