remove promiseHooks stub;

[axe-me]

project using this optionally could at least run, trying to resolve this issue: #6136

What does this PR do?

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

[Jarred-Sumner]

Thank you for this, but this would break libraries which test for the existence of promise hooks in other ways

Instead, we can create a function that masquerades as undefined and then assign the promise hook functions onto that function as well. Then, code which does if (promiseHooks) would return false, but if they were to do promiseHooks.createHook, it will warn