fix(vector): use semantic version comparison for version check

[huayaoyue6]

Summary

Fixes a critical bug in Milvus vector database version comparison that could incorrectly evaluate version requirements for hybrid search functionality.

Problem

The current implementation in MilvusVector._check_hybrid_search_support() and OceanBaseVector._check_hybrid_search_support() uses string comparison of base_version attributes:

String comparison fails for multi-digit version numbers. This could disable hybrid search on newer Milvus versions that actually support it.

Solution

Replace string comparison with proper semantic version comparison using Version objects:

Screenshots

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Checklist

• 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