Fix NPE in EditPostActivty onPostUploaded

[zwarm]

Fixes #20953

This PR addresses a potential NullPointerException in the onPostUploaded event handler by ensuring that the editPostRepository.id is safely accessed. In EditPostActivity, the EventBus is registered before EditPostRepository is fully initialized. As such, there is a risk that an onPostUploaded event might be posted before the EditPostRepository has completed its initialization process, thus causing an NPE when "id" is accessed.

Changes:

• Updated the onPostUploaded method to use val editPostId = editPostRepository.getPost()?.id.
  This ensures that the check post.id == editPostId will fail if editPostRepository.getPost() returns null, preventing a NullPointerException.

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To Test:

As I was unable to recreate the issue, please validate that the Create/Edit post flow works as expected.

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Regression Notes

1. Potential unintended areas of impact
   The crash still occurs

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   Manual testing

3. What automated tests I added (or what prevented me from doing so)
   N/A

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PR Submission Checklist:

• I have completed the Regression Notes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

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Testing Checklist (strike-out the not-applying and unnecessary ones): N/A

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 25.0 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud