Make so explicit class constructor is called in ElasticVectorSearch from_texts (#6199)
Fixes #6198
ElasticKnnSearch.from_texts is actually ElasticVectorSearch.from_texts
and throws because it calls ElasticKnnSearch constructor with the wrong
arguments.
Now ElasticKnnSearch has its own from_texts, which constructs a proper
ElasticKnnSearch.
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Co-authored-by: Charles Parker <charlesparker@FiltaMacbook.local>
Co-authored-by: Bagatur <baskaryan@gmail.com>