fix: persist events after plugin on_event_callback modifications

[Ponts]

Link to Issue or Description of Change

1. Link to an existing issue (if applicable):

• Closes: 3990

Problem:
on_event_callback executes after append_event, preventing plugin modifications from being persisted #3990

Solution:
Run callbacks before persisting events.

Testing Plan

Ran python tests/unittests and verified all tests passed.
There exists tests that verify that events are yielded from the runner.

Unit Tests:

• I have added or updated unit tests for my change.
• All unit tests pass locally.

Manual End-to-End (E2E) Tests:

Checklist

• I have read the CONTRIBUTING.md document.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• I have manually tested my changes end-to-end.
• Any dependent changes have been merged and published in downstream modules.