E2E test: push as regular user in move project spec

What does this MR do and why?

Fixes stale test #409722 (closed)

With !118532 (merged) administrators can no longer push to protected branches (that they don't own/have access to), this test was pushing to a protected branch as admin (i think incorrectly), so this MR changes the test to explicitly push as the protected branch owner.

How to set up and validate locally

QA_LOG_LEVEL=DEBUG QA_GITLAB_URL=http://192.168.4.31:3000 bundle exec rspec qa/specs/features/browser_ui/3_create/repository/move_project_create_fork_spec.rb

MR acceptance checklist

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