Fix Protected Tags show page

What does this MR do and why?

This is the backport of Fix Protected Tags show page. It is a valid candidate for our bug fix backport pilot program

The bug was introduced in 18.0 so a backport is only required for 18-0-stable-ee

Problem

There's currently a bug with the protected tags show page as it returns a 404. This happens because we're missing a show page for the protected tags.

This was introduced in !187054 (merged) but was missed because of the quarantined spec.

Solution

Add the missing page so we can render successfully. Make the quarantine on the protected_tags spec more specific to the flaky specs to re-introduce spec coverage.

Screenshots or screen recordings

Before	After
Screen_Recording_2025-06-03_at_06.46.46	Screen_Recording_2025-06-03_at_06.42.14

MR acceptance checklist

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

• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch.
• The MR that fixed the bug on the default branch has been deployed to GitLab.com (not applicable for documentation or spec changes).
• This MR has a severity label assigned (if applicable).
• Set the milestone of the merge request to match the target backport branch version.
• This MR has been approved by a maintainer (only one approval is required).
• Ensure the e2e:test-on-omnibus-ee job has either succeeded or been approved by a Software Engineer in Test.

Note to the merge request author and maintainer

If you have questions about the patch release process, please:

• Refer to the patch release runbook for engineers and maintainers for guidance.
• Ask questions on the #releases Slack channel (internal only).