Fix: ensure that the dirty state is correctly set even when the current save operation is canceled (#15308).

[lessmost]

What it does

fix issue #15308

How to test

1. Open an text file
2. Make some edits, and intermediately press cmd/ctrl+s twice quickly
3. Note that the editor's dirty state icon will correctly disappear.

Follow-ups

Breaking changes

• This PR introduces breaking changes and requires careful review. If yes, the breaking changes section in the changelog has been updated.

Attribution

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[msujew]

Thank you for the contribution @lessmost, looks good to me 👍