fix(cppgc): removed deleted cstors in CppHeapCreateParams

In the C++20 a following paper was implemented [1]. This
paper makes code below illformed. The high level idea is
that as soon as class gets non default constructor - all
default initializations are not added implicitly.

class A {
public:
  A(const A&) = delete;
};

int main() {
  A a{};
  return 0;
}

So if V8 embedder is building its code with C++20 it can
not initialize v8::CppHeapCreateParams struct and as a
result can not create a CppHeap.

One of the possible mitigations (3.3) from the paper is
to add non copyable field into class. Luckily there
is std::vector<std::unique_ptr>> in this class already.

[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1008r1.pdf

Change-Id: I8a2dc35784d7646b5f73a5e178716e9bf2ffe601
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3348007Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Alexey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78504}

include/v8-cppgc.h

@@ -78,9 +78,6 @@ struct WrapperDescriptor final {
 };
 
 struct V8_EXPORT CppHeapCreateParams {
-  CppHeapCreateParams(const CppHeapCreateParams&) = delete;
-  CppHeapCreateParams& operator=(const CppHeapCreateParams&) = delete;
-
   std::vector<std::unique_ptr<cppgc::CustomSpaceBase>> custom_spaces;
   WrapperDescriptor wrapper_descriptor;
 };