Bump Microsoft.AspNetCore.TestHost from 3.1.7 to 3.1.8

Bumps [Microsoft.AspNetCore.TestHost](https://github.com/aspnet/AspNetCore) from 3.1.7 to 3.1.8.
- [Release notes](https://github.com/aspnet/AspNetCore/releases)
- [Commits](dotnet/aspnetcore@v3.1.7...v3.1.8)

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

tests/NetDaemon.Daemon.Tests/NetDaemon.Daemon.Tests.csproj

@@ -16,7 +16,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="3.1.7" />
+    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="3.1.8" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.0" />
     <PackageReference Include="Moq" Version="4.14.5" />
     <PackageReference Include="xunit" Version="2.4.1" />

tests/NetDaemon.Test/NetDaemon.Test.csproj

@@ -26,7 +26,7 @@
   </ItemGroup>
 
     <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="3.1.7" />
+    <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="3.1.8" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.0" />
     <PackageReference Include="Moq" Version="4.14.5" />
     <PackageReference Include="xunit" Version="2.4.1" />