[databases]: change Opensearch ism_history_max_docs type to int64 to …

[loosla]

…align with api

This PR changes a type for Opensearch ism_history_max_docs to int64

Because DigitalOcean API doesn't accept value that exceeds int64 max limit.

[bentranter]

This changes a type on a struct field that was already released, so this is technically a breaking change. I'm not sure if it's better to apply this breaking change since it's unlikely that anyone is already using this, but I also think it's unlikely that anyone will set the value anything greater than max uint64 (which is 18,446,744,073,709,551,615).

Maybe instead, we can add a note about the limitation that this should only be positive numbers in the doc string, and add a validation to prevent negative numbers from being submitted to the API?

[andrewsomething]

@bentranter I don't believe this has been part of a tagged release yet. OpensearchConfig was added in #729

[loosla]

@bentranter We check the value to be >= 1 on our API side.

curl -X PATCH   -H "Content-Type: application/json"   -H "Authorization: Bearer $DIGITALOCEAN_TOKEN"   -d '{"config": {"ism_history_max_docs": 0}}'   "https://api.digitalocean.com/v2/databases/d79e2e2b-3493-4523-9352-4ec9ace11b08/config"

{"message":"invalid 'user_config': invalid input for opensearch: 0 is less than the minimum of 1","id":"unprocessable_entity","request_id":"6edcbe86-3d6a-4242-b50e-4f072901a9ad"}

It wasn't released yet

[bentranter]

@andrewsomething @loosla Ah sorry about that, my bad – I got the wrong commit SHA from the git blame for that field. This change LGTM then!