Quarantine failing tests (#37916)

src/Servers/IIS/IIS/test/Common.FunctionalTests/StartupTests.cs

@@ -450,6 +450,7 @@ namespace Microsoft.AspNetCore.Server.IIS.FunctionalTests
 
         [ConditionalFact]
         [RequiresNewHandler]
+        [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/37915")]
         public async Task StartupTimeoutIsApplied()
         {
             // From what we can tell, this failure is due to ungraceful shutdown.

src/Servers/Kestrel/test/Interop.FunctionalTests/Http3/Http3RequestTests.cs

@@ -1570,6 +1570,7 @@ namespace Interop.FunctionalTests.Http3
         [MsQuicSupported]
         [InlineData(HttpProtocols.Http3)]
         [InlineData(HttpProtocols.Http2)]
+        [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/35070")]
         public async Task GET_GracefulServerShutdown_RequestCompleteSuccessfullyInsideHostTimeout(HttpProtocols protocol)
         {
             // Arrange