Clarify who has permission to create test cases

What does this MR do and why?

Initially came to my attention via !102020 (comment 1153542986) and I noted it's perhaps not quite clear on who has the correction permissions to create test case issues for E2E tests.

This MR updates the documentation relating to linking E2E test cases to the Quality Test Cases project, helping ensure there is clarity that 'any team member' can help in creating a test case.

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