fix: NULL embeddings bug

[pecastro]

Summary

This fix ensures that NULL embedding don't make it to the DB in case of excessive 429 errors when the embedder is running with enable_batch false.
In scenarios where the embedder endpoint is overloaded, returning 429s and the httpx instance exhausts it's max_retries count, this bug was being responsible for the creation of DB records whose embeddings field was NULL.

(If applicable, issue number: #7567)

Type of change

• Bug fix
• New feature
• Breaking change
• Improvement
• Model update
• Other:

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Checklist

• Code complies with style guidelines
• Ran format/validation scripts (./scripts/format.sh and ./scripts/validate.sh)
• Self-review completed
• Documentation updated (comments, docstrings)
• Examples and guides: Relevant cookbook examples have been included or updated (if applicable)
• Tested in clean environment
• Tests added/updated (if applicable)

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Additional Notes

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PR Triage

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