[dotnet-linker] Only use the new SetTypeMapEntryAssemblyStep on .NET 10.

The step is only needed on .NET 10, so:

* Condition the item group in Xamarin.Shared.Sdk.targets on the target
  framework version being less than 11.0.
* Surround the step itself with '#if !NET11_0_OR_GREATER', so that it isn't
  even compiled on .NET 11+.

Also revert the change to tests/common/shared-dotnet.mk, that's fixed in a
separate pull request.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3f879a89-7c49-4886-93e9-e43d848c5846

Author: rolfbjarne

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -977,11 +977,13 @@
 			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Type="Xamarin.Linker.DoneStep" Condition="'$(PostProcessAssemblies)' != 'true'" />
 		</ItemGroup>
 
-		<ItemGroup Condition="'$(PrepareAssemblies)' == 'true' And '$(Registrar)' == 'trimmable-static'">
+		<ItemGroup Condition="'$(PrepareAssemblies)' == 'true' And '$(Registrar)' == 'trimmable-static' And $([MSBuild]::VersionLessThan($(TargetFrameworkVersion), '11.0'))">
 			<!--
 				This step must run even when all our other custom steps are disabled (which happens when both
 				PrepareAssemblies and PostProcessAssemblies are true), because otherwise ILLink will remove the
 				type map attributes from the type map assemblies the trimmable registrar generated before ILLink ran.
+
+				It's not needed on .NET 11+, because there we pass the typemap-entry-assembly argument to ILLink instead.
 			-->
 			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" BeforeStep="MarkStep" Type="Xamarin.Linker.SetTypeMapEntryAssemblyStep" />
 		</ItemGroup>

tests/common/shared-dotnet.mk

@@ -199,7 +199,7 @@ delete-saved-state:
 
 run-bare: delete-saved-state
 	$(Q) $(EXECUTABLE) --autostart --autoexit $(RUN_ARGUMENTS)
-	$(Q) $(MAKE) delete-saved-state RUNTIMEIDENTIFIER= RUNTIMEIDENTIFIERS=
+	$(Q) $(MAKE) delete-saved-state
 
 # Get the list of applicable simulators, and pick the first in the list.
 # Make sure to have a matching simulator runtime installed, otherwise this won't work.

tools/dotnet-linker/Steps/SetTypeMapEntryAssemblyStep.cs

@@ -1,6 +1,9 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+// This step is only needed on .NET 10, where ILLink doesn't have the '--typemap-entry-assembly' option.
+#if !NET11_0_OR_GREATER
+
 using System.IO;
 
 using Xamarin.Bundler;
@@ -17,8 +20,7 @@ namespace Xamarin.Linker {
 	// type map assemblies the trimmable registrar generates, leaving the app with empty type maps at runtime.
 	//
 	// So tell ILLink about the entry assembly ourselves when ILLink didn't figure it out on its own (in
-	// .NET 11+ we pass '--typemap-entry-assembly' to ILLink instead, which takes precedence over the entry
-	// assembly, so there this step does nothing of consequence).
+	// .NET 11+ we pass '--typemap-entry-assembly' to ILLink instead, so there this step isn't needed at all).
 	public class SetTypeMapEntryAssemblyStep : ConfigurationAwareStep {
 		protected override string Name { get; } = "SetTypeMapEntryAssembly";
 		protected override int ErrorCode { get; } = 2530;
@@ -51,3 +53,5 @@ protected override void TryProcess ()
 		}
 	}
 }
+
+#endif // !NET11_0_OR_GREATER