Fix test-e2e-local when building artifacts locally (#43043)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/43043

Restores behaviour of `yarn test-e2e-local` when we are not using `--circleciToken`. The `npm pack` logic (necessary for the subsequent `updateTemplatePackage` call before initing `RNTestProject`) was deleted in https://github.com/facebook/react-native/pull/41172 / D50651448.

https://github.com/facebook/react-native/commit/4eed12b7df5d9731e556b77d701c87dcf91d3a1f#diff-56f57bf0eac99b0fda1b2938aceb8d9b663db82c07cb405bd53a01c8689710ffL224-L240

Changelog: [Internal]

Reviewed By: cipolleschi

Differential Revision: D53806191

fbshipit-source-id: 918306d5dea90266292728cda9c0e243e5c37eba