Soft validation on environment external URL

What does this MR do and why?

Previously, we merged this MR to resolve the issue, however, we reverted it because it resulted in ~"master:broken". This MR is exactly the same with the previous MR, except that it contains a patch for the master:broken issue. This patch is highlighted in this commit.

A few notes:

• We've also added a new test case to make sure that this MR is safe for master branch.
• We've also added ~pipeline:run-all-* labels to this MR for running full-fledged pipelines. These pipelines contain gitlab:setup job.

Screenshots or screen recordings

Same with !91970 (merged)

How to set up and validate locally

Same with !91970 (merged)

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.