Bump Microsoft.AspNetCore.TestHost from 9.0.2 to 9.0.3

Bumps [Microsoft.AspNetCore.TestHost](https://github.com/dotnet/aspnetcore) from 9.0.2 to 9.0.3.
- [Release notes](https://github.com/dotnet/aspnetcore/releases)
- [Changelog](https://github.com/dotnet/aspnetcore/blob/main/docs/ReleasePlanning.md)
- [Commits](dotnet/aspnetcore@v9.0.2...v9.0.3)

---
updated-dependencies:
- dependency-name: Microsoft.AspNetCore.TestHost
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

test/SlowDown.Tests/SlowDown.Tests.csproj

@@ -24,11 +24,11 @@
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.2" />
-    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="9.0.2" />
+    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="9.0.3" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.2" />
-    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="9.0.2" />
+    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="9.0.3" />
   </ItemGroup>
 
   <ItemGroup>