Out of ordering of requests to opensearch

Hi Team,

We are seeing an out of order problem for the requests to opensearch when using `index.write.method=upsert`.

However we don't see this issue when we set `index.write.method=insert`.

Below is our connector config

`connector.class=io.aiven.kafka.connect.opensearch.OpensearchSinkConnector`
`behavior.on.null.values=delete`
`transforms.extractKey.field=id`
`index.write.method=insert`
`connection.password=`
`tasks.max=10`
`topics=dev.task`
`batch.size=10000`
`transforms=extractKey`
`key.ignore=false`
`max.in.flight.requests=5`
`key.ignore.id.strategy=none`
`transforms.extractKey.type=org.apache.kafka.connect.transforms.ExtractField$Key`
`schema.ignore=true`
`key.converter.schemas.enable=false`
`flush.timeout.ms=300000`
`value.converter.schemas.enable=false`
`value.converter=org.apache.kafka.connect.json.JsonConverter`
`connection.url=...`
`key.converter=org.apache.kafka.connect.json.JsonConverter`
`behavior.on.version.conflict=warn`
`schemas.enable=false`