Update RestSharp requirement from 108.0.* to 109.0.*

Updates the requirements on [RestSharp](https://github.com/restsharp/RestSharp) to permit the latest version.
- [Release notes](https://github.com/restsharp/RestSharp/releases)
- [Commits](restsharp/RestSharp@108.0.0...109.0.1)

---
updated-dependencies:
- dependency-name: RestSharp
  dependency-type: direct:production
...

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

Author: dependabot[bot]

src/TestClient/TestClient.csproj

@@ -5,6 +5,6 @@
 		<IsPackable>false</IsPackable>
 	</PropertyGroup>
 	<ItemGroup>
-		<PackageReference Include="RestSharp" Version="108.0.*" />
+		<PackageReference Include="RestSharp" Version="109.0.*" />
 	</ItemGroup>
 </Project>