Elasticsearch: Update required database version to 7.16

[gabor]

Our supported-versions policy for Elasticsearch is: we support Elasticsearch versions that Elasticsearch-the-company supports.

the current info can be found at: https://www.elastic.co/support/eol

the support for elastic 7.15.x ended at 2023-03-22, so we will only support versions 7.16.x or higher.

(NOTE: the way this works is: you will still be able to use an older version of elasticsearch, but you will get warnings in the query-editor and in the datasource-config if you run an unsupported elasticsearch version)

(fixes #65908)

Release notice breaking change

Grafana requires an Elasticsearch version of 7.16 or newer. If you use an older Elasticsearch version, you will get warnings in the query editor and on the datasource configuration page.

[github-actions]

Backend code coverage report for PR #66928
No changes

[github-actions]

Frontend code coverage report for PR #66928

Plugin	Main	PR	Difference
elasticsearch	78.43%	78.43%	0%

[ivanahuckova]

Nice! LGTM. Do we want to mark it as breaking change? 🤔

[gabor]

@ivanahuckova :

Nice! LGTM. Do we want to mark it as breaking change? 🤔

hmm.. good point, i don't know:

• pro:
  • it is technically a change. people will get a warning-box where they did not get it before.
  • if we are unsure, it's better to mention it instead of not mentioning it
• con:
  • nothing breaks, you only get a red warning-box above your query-builder
  • we did not change the "support what is not end-of-life" policy, so this is not even a "change" as such

need to think a bit more about this 😄