E2E: Add a script to remove run e2e note from MRs with specified label

What does this MR do and why?

Related to gitlab-org/quality/quality-engineering/team-tasks#2206

Adds a script to remove comments prompting to run trigger-omnibus-and-follow-up-e2e job on MRs with specified labels.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

From the qa/qa/tools directory, run:

PROJECT_ID=<project_id> ACCESS_TOKEN="<access_token>" LABEL="<label>" ./remove_run_e2e_notes.rb

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.