Service Desk: When editing an internal note, the external participants notification warning should not be shown

Summary

1. When you edit an internal comment on a Service Desk issue, you'll see the external participants notification warning. This should not happen, as it's an internal note and internal notes won't notify external participants.
2. Additionally when you reply to an internal note it also displays the external participants notification warning, which is also not correct. Child notes on an internal comment are always internal notes and won't send any notifications to external parties.

Steps to reproduce

For 1):

• Access a Service Desk issue
• Write an internal note
• Edit this internal note. You should see the content editor with the warning XX will be notified of your comment.

For 2):

• Draft a reply to the created internal note. You should see the warning XX will be notified of your comment.

Example Project

https://gitlab.com/gitlab-org/incubation-engineering/service-desk/service-desk-test-project/-/issues/7

What is the current bug behavior?

You can see the XX will be notified of your comment. warning below the content editor.

What is the expected correct behavior?

You should not see the ``XX will be notified of your comment.` warning below the content editor for an internal comment.

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com

Results of GitLab environment info

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Results of GitLab application Check

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Possible fixes

We should not display the warning when the user edits an internal comment. Maybe we should generally omit this message in the editing mode, because we do not send or resend notification emails after the initial creation of a comment.