Cosmonauts: Migrate analytics-api from ElasticSearch to OpenSearch

[UsamaSadiq]

Description

• An initial discovery has been done to find the usages of Elastic Search in analytics-api. Coordinate with the cosmonauts team to get analytics-api completely migrated from using ElasticSearch to OpenSearch instead.
• An Architecture Decision Record (ADR) document will be created by the owning team and shared with the community on this issue.

Further Context

Further details and context on the issue can be found on openedx/public-engineering#16

[schenedx]

This is already complete. The Cosmonauts team determined the Learner Analytics view on insights service was not a feature justifying its cost. Therefore the view was removed. The Elastic Search instances supporting that view was also removed. There is no longer a connection between Insights analytics data with ElasticSearch.
The only tail of this work is that, there are still references of ES in edx-analytics-data-api repository. That work is tracked with https://2u-internal.atlassian.net/browse/MST-1851. This issue should be moved to Done column