[8.12] Remove Gainsight from cloud plugin (#172318)

[bollinic]

Backport

This will backport the following commits from main to 8.12:

• Remove Gainsight from cloud plugin (#172318)

Questions ?

Please refer to the Backport tool documentation

[github-actions]

Documentation preview:

• ✨ Changed pages

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: ea618ea
• Storybooks Preview

Failed CI Steps

• Defend Workflows Cypress Tests #14

Test Failures

• [job] [logs] Defend Workflows Cypress Tests #14 / Response console From Cases should open responder should open responder

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
cloudGainsight	7	-	-7

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
@kbn/analytics-shippers-gainsight	2	-	-2

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
cloudGainsight	2.1KB	-	-2.1KB

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
cloudGainsight	3.5KB	-	-3.5KB

Unknown metric groups

API count

id	before	after	diff
@kbn/analytics-shippers-gainsight	18	-	-18

async chunk count

id	before	after	diff
cloudGainsight	1	-	-1

ESLint disabled in files

id	before	after	diff
@kbn/analytics-shippers-gainsight	1	-	-1
cloudGainsight	2	-	-2
total			-3

ESLint disabled line counts

id	before	after	diff
cloudGainsight	1	-	-1

Total ESLint disabled count

id	before	after	diff
@kbn/analytics-shippers-gainsight	1	-	-1
cloudGainsight	3	-	-3
total			-4

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

[alisonelizabeth]

Backport LGTM. I noticed the CODEOWNERS file was left out of the changeset, but IIRC that only exists main