jest-haste-map: duplicate manual mock found: next/config

jest will complain if we have more than one manual mock on the same module, even when they are placed in a different location:

NODE_ENV=test ./node_modules/.bin/jest --verbose src/__tests__/client/helpers/newrelic-enabled/loggingUtilNewRelicEnabled.test.js

jest-haste-map: duplicate manual mock found: next/config
  The following files share their name; please delete one of them:
    * <rootDir>/src/__tests__/client/helpers/newrelic-disabled/__mocks__/next/config.js
    * <rootDir>/src/__tests__/client/helpers/newrelic-enabled/__mocks__/next/config.js

 PASS  src/__tests__/client/helpers/newrelic-enabled/loggingUtilNewRelicEnabled.test.js
  newrelicUtil: ENABLE_NEWRELIC is set to true
    generateSomething
      ✓ if the required env for New Relic Browser agent is set then return NREUM string (3ms)



Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        1.288s
Ran all test suites matching /src\/__tests__\/client\/helpers\/newrelic-enabled\/loggingUtilNewRelicEnabled.test.js/i.