fix: add missing onSuccess to DeleteRole.tsx

[Asraye]

This PR adds the missing onSuccess to DeleteRole.tsx. Now successfully pushes the user back to the main roles window.

Fixes #1137

How was this PR tested?

Locally tested via making a role called "Test" and deleting it.

Screenshots & Screencasts (if appropriate)

Checklist:

• I have carefully read the contributing guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation if applicable
• I have no unrelated changes in the PR
• I have confirmed that any new dependencies are strictly necessary
• I have written tests for new code (if applicable)
• I have followed naming conventions/patterns in the surrounding code

Please declare, if any, LLM usage involved in creating this PR

None
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[Dadadah]

Thanks for your contribution. We'll get this merged after 0.8.0 releases.