LibJS+LibWeb: Rename Heap::allocate_without_realm to Heap::allocate

Now that the heap has no knowledge about a JavaScript realm and is
purely for managing the memory of the heap, it does not make sense
to name this function to say that it is a non-realm variant.

Libraries/LibWeb/Fetch/Infrastructure/FetchController.cpp

@@ -20,7 +20,7 @@ FetchController::FetchController() = default;
 
 JS::NonnullGCPtr<FetchController> FetchController::create(JS::VM& vm)
 {
-    return vm.heap().allocate_without_realm<FetchController>();
+    return vm.heap().allocate<FetchController>();
 }
 
 void FetchController::visit_edges(JS::Cell::Visitor& visitor)