Incorrectly ingesting templates in Elasticsearch >=7.8

[itsbicb4]

In version of Elasticsearch 7.8 "template" api's were deprecated and replaced with "index_template" api's

GET _template # old way
GET _index_template # current way

Since last v7 of elasticsearch was 7.17 and current version of elasticsearch is 8.17 i think this should be replaced with support of only new way or at least add feature to chose in datahub recipes which index template api to use.

New: https://www.elastic.co/guide/en/elasticsearch/reference/current/index-templates.html
Legacy: https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-templates-v1.html

In code template functions should be replace with new index_template functions
indices.get_template -> indices.get_index_template
Docs: https://elasticsearch-py.readthedocs.io/en/v8.17.1/api/indices.html

Wrong code example:

datahub/metadata-ingestion/src/datahub/ingestion/source/elastic_search.py

Line 389 in 412600a

templates = self.client.indices.get_template()