fix: MockK8s/MockK8s.csproj to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DOTNET-SYSTEMTEXTJSON-7433719

Author: snyk-bot

MockK8s/MockK8s.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="KubernetesClient" Version="14.0.2" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.5" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.7" />
     <PackageReference Include="Nito.AsyncEx" Version="5.1.2" />
     <PackageReference Include="System.Reactive" Version="6.0.1" />
     <PackageReference Include="xunit.abstractions" Version="2.0.3" />