Warmup API does not work for files created with older version of libs

[jmazanec15]

Description

The warmup API decides what segments to load based on the file name it would build for the segments: https://github.com/opensearch-project/k-NN/blob/main/src/main/java/org/opensearch/knn/index/KNNIndexShard.java#L129-L130. The problem with this is that for segment files built with older versions of a library, the lib version is included in the file name. This leads to these files getting skipped during warmup

Proposed solution

Update warmup API logic to get files in a backwards compatible manner.