[release/7.0] Don't try to build PGO tools on platforms with no CoreCLR port. (#75003)

Co-authored-by: Jo Shields <directhex@apebox.org>

Author: github-actions[bot]

eng/Subsets.props

@@ -61,7 +61,8 @@
     <DefaultMonoSubsets Condition="'$(MonoAOTEnableLLVM)' == 'true' and '$(MonoAOTLLVMDir)' == ''">mono.llvm+</DefaultMonoSubsets>
     <DefaultMonoSubsets Condition="'$(TargetOS)' == 'Browser'">$(DefaultMonoSubsets)mono.wasmruntime+</DefaultMonoSubsets>
     <DefaultMonoSubsets Condition="'$(MonoCrossAOTTargetOS)' != ''">$(DefaultMonoSubsets)mono.aotcross+</DefaultMonoSubsets>
-    <DefaultMonoSubsets>$(DefaultMonoSubsets)mono.runtime+mono.corelib+mono.packages+mono.tools+</DefaultMonoSubsets>
+    <DefaultMonoSubsets>$(DefaultMonoSubsets)mono.runtime+mono.corelib+mono.packages+</DefaultMonoSubsets>
+    <DefaultMonoSubsets Condition="'$(PrimaryRuntimeFlavor)' != 'Mono'">$(DefaultMonoSubsets)mono.tools+</DefaultMonoSubsets>
     <DefaultMonoSubsets Condition="'$(TargetsMobile)' != 'true'">$(DefaultMonoSubsets)host.native+</DefaultMonoSubsets>
 
     <DefaultLibrariesSubsets Condition="'$(BuildTargetFramework)' == '$(NetCoreAppCurrent)' or