fix annotation failed when embedding model and dimension changed

[JohnJyong]

Summary

fix annotation failed when embedding model and dimension changed

Tip

Close issue syntax: Fixes #<issue number> or Resolves #<issue number>, see documentation for more details.

fix #17327
close #17328

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Checklist

Important

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• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods

[Copilot]

Pull Request Overview

This PR addresses an issue where annotation failures occurred when the embedding model and dimension changed. The changes update the deletion process for old annotation indexes in both enable and disable annotation tasks.

• Update deletion logic in enable_annotation_reply_task to remove old embedding vectors.
• Replace metadata-specific deletion with a broader deletion in disable_annotation_reply_task.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
api/tasks/annotation/enable_annotation_reply_task.py	Adds logic to delete the old annotation embedding vector based on the previous collection binding settings.
api/tasks/annotation/disable_annotation_reply_task.py	Updates annotation index deletion by switching from metadata-based deletion to deleting the entire vector.

Comments suppressed due to low confidence (1)

api/tasks/annotation/disable_annotation_reply_task.py:49

• Verify that replacing vector.delete_by_metadata_field with vector.delete does not unintentionally delete records beyond those associated with the current annotation.

vector.delete()