FIX Remove redundant memoisation

[GuySartorelli]

Don't squash

There are two commits here.

Commit one

Required to resolve a false-negative result in cms jest test:

Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons:
1. You might have mismatching versions of React and the renderer (such as React DOM)
2. You might be breaking the Rules of Hooks
3. You might have more than one copy of React in the same app
See https://fb.me/react-invalid-hook-call for tips about how to debug and fix this problem.

Obviously that is nonsense - but this memoisation is redundant anyway, since we're storing the result as a global variable.

Commit two

Removes redundant reference to "jasmine" which isn't used anymore and isn't available.

Parent issue

• CMS 5: Fix broken JavaScript tests #1421