[FEATURE] Evict graphs from cache when index is closed or delete for indices that are created using NativeEngines990KnnVectorsFormat

[VijayanB]

Is your feature request related to a problem?
This PR #1946 clears graph from cache whenever index is closed or deleted to save memory. However this works only for indices created using BinaryDocValues. With 2.17. k-NN uses NativeEngines990KnnVectorsFormat, hence, we need similar feature for indices that are created using this new format.

What solution would you like?
Evict graph when index is closed or deleted irrespective of vector format.

What alternatives have you considered?
N/A

Do you have any additional context?
N/A

[navneet1v]

@0ctopus13prime do you want to pick this task up as part of removing the file watcher dependency from k-NN plugin?

[0ctopus13prime]

@navneet1v
Hi Navneet! Sorry, I just saw your comment.
And as you know, the related PR was merged for both main and 2.x, I think we can close this out!

[navneet1v]

Closing out this issue after getting confirmation from @0ctopus13prime