Fix filtered knn vector search when query timeouts are enabled

[benwtrent]

Turns out when we have query cancellation checks turned on, we wrap the filter bitset, meaning we cannot actually see that the inner Bits is a bitset.

This is important for the hnsw knn format readers, see:

https://github.com/apache/lucene/blob/1584c05b27ac31fbccb0ab328bf9f8eb6a7de414/lucene/core/src/java/org/apache/lucene/codecs/lucene99/Lucene99HnswVectorsReader.java#L335

I am not sure how to actually test this.

Related: https://github.com/elastic/elasticsearch/pull/126876

[elasticsearchmachine]

Pinging @elastic/es-search-relevance (Team:Search Relevance)

[elasticsearchmachine]

Hi @benwtrent, I've created a changelog YAML for you.