Bump RestSharp from 106.11.7 to 106.12.0 in /ApiClient.Tests

Bumps [RestSharp](https://github.com/restsharp/RestSharp) from 106.11.7 to 106.12.0.
- [Release notes](https://github.com/restsharp/RestSharp/releases)
- [Commits](restsharp/RestSharp@106.11.7...106.12)

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

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

Author: dependabot[bot]

ApiClient.Tests/ApiClient.Tests.csproj

@@ -14,7 +14,7 @@
     <PackageReference Include="MSTest.TestAdapter" Version="2.1.1" />
     <PackageReference Include="MSTest.TestFramework" Version="2.1.1" />
     <PackageReference Include="WireMock.Net" Version="1.4.20" />
-    <PackageReference Include="RestSharp" Version="106.11.7" />
+    <PackageReference Include="RestSharp" Version="106.12.0" />
   </ItemGroup>
 
   <ItemGroup>