Remove incident edit button when not on Summary

What does this MR do and why?

Describe in detail what your merge request does and why.

Edit button for incident title and description is only shown when on summary tab.

Currently the component accesses the DOM directly rather than using Vue, created #361618 to address this.

closes #356713 (closed)

Screenshots or screen recordings

These are strongly recommended to assist reviewers and reduce the time to merge your change.

Summary Tab	Metrics Tab

How to set up and validate locally

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

1. create an incident on any project (navigate to project, select Monitor->Incidents->Create Incident
2. open incident
3. navigate to a tab other than summary

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.