Remove `index.ttl.disable_purge`

[clintongormley]

TTL is no longer supported and the index.ttl.disable_purge setting can be removed.

[PnPie]

I make one PR for this one :)

[videetssinghai]

I would like to make a PR for this one if this issue is still open

[videetssinghai]

Ok so I found "index.ttl.disable_purge" in 3 files - IndexScopedSettings, IndexSettings and IndexSettingsTest. How do I remove it ? ( straight away remove its functions and tests without affecting the other code ?)

[videetssinghai]

@clintongormley

[javanna]

hi @videetssinghai there is already a PR waiting for review that fixes this issue, see #27589 .

[elasticmachine]

Pinging @elastic/es-core-infra

[DaveCTurner]

Sorry, I didn't see this was open. It was deprecated in #29526 and closed in #29527, so this can be closed.