fix: raise errors when indexing option methods are not supported

[georgeh0]

stop gap for #1051

[Copilot]

Pull Request Overview

This PR adds validation to prevent the use of unsupported vector indexing configuration options across multiple database targets. The changes ensure that appropriate error messages are raised when users attempt to configure vector index methods or vector indexes themselves on targets that don't yet support these features.

Key changes:

• Add method configuration validation for Qdrant and Neo4j targets
• Add vector index support validation for Kuzu and LanceDB targets

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/ops/targets/qdrant.rs	Adds validation to reject vector index method configuration
src/ops/targets/neo4j.rs	Adds validation to reject vector index method configuration
src/ops/targets/kuzu.rs	Adds validation to reject vector indexes entirely
python/cocoindex/targets/lancedb.py	Adds validation to reject vector index method configuration

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