Revert "Fix ShuffleThunk cache heap (#105480)"

This reverts commit 81976ed.

src/coreclr/vm/loaderallocator.cpp

@@ -1734,7 +1734,11 @@ void AssemblyLoaderAllocator::Init(AppDomain* pAppDomain)
     LoaderAllocator::Init((BaseDomain *)pAppDomain);
     if (IsCollectible())
     {
-        m_pShuffleThunkCache = new ShuffleThunkCache(m_pStubHeap);
+        // TODO: the ShuffleThunkCache should really be using the m_pStubHeap, however the unloadability support
+        // doesn't track the stubs or the related delegate classes and so we get crashes when a stub is used after
+        // the AssemblyLoaderAllocator is gone (the stub memory is unmapped).
+        // https://github.com/dotnet/runtime/issues/55697 tracks this issue.
+        m_pShuffleThunkCache = new ShuffleThunkCache(SystemDomain::GetGlobalLoaderAllocator()->GetExecutableHeap());
     }
 }