Bump GitHub.Copilot.SDK from 1.0.0-beta.2 to 1.0.8

---
updated-dependencies:
- dependency-name: GitHub.Copilot.SDK
  dependency-version: 1.0.8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Directory.Packages.props

@@ -29,7 +29,7 @@
     <PackageVersion Include="Microsoft.Extensions.AI" Version="10.5.2" />
     <PackageVersion Include="Microsoft.Extensions.AI.Abstractions" Version="10.5.2" />
     <PackageVersion Include="Microsoft.Extensions.AI.OpenAI" Version="10.5.2" />
-    <PackageVersion Include="GitHub.Copilot.SDK" Version="1.0.0-beta.2" />
+    <PackageVersion Include="GitHub.Copilot.SDK" Version="1.0.8" />
     <PackageVersion Include="Markdig.Signed" Version="1.0.0" />
     <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.7" />
     <PackageVersion Include="Microsoft.Extensions.Logging.Console" Version="10.0.7" />