Update dependency Microsoft.AspNetCore.Mvc.Testing to v9

Author: dependencyupdates[bot]

src/Directory.Packages.props

@@ -17,7 +17,7 @@
     <PackageVersion Include="Fody" Version="6.9.1" />
     <PackageVersion Include="GitHubActionsTestLogger" Version="2.4.1" />
     <PackageVersion Include="HdrHistogram" Version="2.5.0" />
-    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.17" />
+    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.8" />
     <PackageVersion Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.17" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="8.0.1" />
     <PackageVersion Include="Microsoft.Extensions.DependencyModel" Version="8.0.2" />