[Meta] Promote searchable snapshot out of experimental

[andrross]

This is a meta task to track the work required to promote the searchable snapshot feature out from behind the experimental feature flag to a production ready feature.

• [Searchable Snapshot] Design file caching mechanism for block based files #4964
• [Searchable Snapshot] Implement FileSystem Tracking LRU Cache with RefCounting #4965
• [Searchable Snapshot] Finalize behavior of settings API #4966
• [Searchable Snapshot] Prevent deletion of snapshots that are backing searchable snapshot indexes #4967
• [Searchable Snapshot] Define additional metrics needed for searchable snapshots #4968
• [Searchable Snapshot] Capture initial CPU profiling information #5217
• [Searchable Snapshot] Add first class support to test performance for searchable snapshot in opensearch-benchmark #5218
• [Searchable Snapshot] IndexInput clones close handling #5243
• [Searchable Snapshot] Add Integ test to make there is no resource leak #5244
• [Searchable Snapshot] Implement disk reservation logic to be used for local file system cache #5508
• [Searchable Snapshot] Add listener to Index events to update local file system cache entries #5981
• [Searchable Snapshots] Prevent search node startup if there are more than a single data path #6274

[anasalkouz]

Now, you can track the progress of Searchable Snapshots on this board.
If you are interested and want to contribute, feel free to pick any of the pending task.
cc: @reta

[DarshitChanpura]

Hey @anasalkouz @andrross . Can we close this issue as completed for v2.7.0 release, since all associated subtasks have been completed?