[9.1] [UII] Unskip data streams list tests (elastic#231549) (elastic#231709)

# Backport

This will backport the following commits from `main` to `9.1`:
- [[UII] Unskip data streams list tests
(elastic#231549)](elastic#231549)

<!--- Backport version: 9.6.6 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

<!--BACKPORT [{"author":{"name":"Jen
Huang","email":"[email protected]"},"sourceCommit":{"committedDate":"2025-08-13T20:24:08Z","message":"[UII]
Unskip data streams list tests (elastic#231549)\n\n## Summary\n\nResolves
elastic#211515. Found an old ES promotion issue which caused this test\nsuite
to be skipped. The underlying ES issue looks to be resolved so\nthis can
be un-skipped. Passed locally with current & snapshot
ES\nversions.\n\nBackporting to 9.1 as it was originally skipped
there.","sha":"b9e7cded04fc9b3a769d2fbe9fd0e6f8d240aa27","branchLabelMapping":{"^v9.2.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:skip","Team:Fleet","backport:prev-minor","v9.2.0"],"title":"[UII]
Unskip data streams list
tests","number":231549,"url":"https://github.com/elastic/kibana/pull/231549","mergeCommit":{"message":"[UII]
Unskip data streams list tests (elastic#231549)\n\n## Summary\n\nResolves
elastic#211515. Found an old ES promotion issue which caused this test\nsuite
to be skipped. The underlying ES issue looks to be resolved so\nthis can
be un-skipped. Passed locally with current & snapshot
ES\nversions.\n\nBackporting to 9.1 as it was originally skipped
there.","sha":"b9e7cded04fc9b3a769d2fbe9fd0e6f8d240aa27"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v9.2.0","branchLabelMappingKey":"^v9.2.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/231549","number":231549,"mergeCommit":{"message":"[UII]
Unskip data streams list tests (elastic#231549)\n\n## Summary\n\nResolves
elastic#211515. Found an old ES promotion issue which caused this test\nsuite
to be skipped. The underlying ES issue looks to be resolved so\nthis can
be un-skipped. Passed locally with current & snapshot
ES\nversions.\n\nBackporting to 9.1 as it was originally skipped
there.","sha":"b9e7cded04fc9b3a769d2fbe9fd0e6f8d240aa27"}}]}]
BACKPORT-->

Co-authored-by: Jen Huang <[email protected]>

Author: kibanamachine

x-pack/platform/test/fleet_api_integration/apis/data_streams/list.ts

@@ -105,9 +105,7 @@ export default function (providerContext: FtrProviderContext) {
     return await supertest.get(`/api/fleet/data_streams`).set('kbn-xsrf', 'xxxx');
   };
 
-  // Failing ES Promotion: https://github.com/elastic/kibana/issues/151756
-  // Failing: See https://github.com/elastic/kibana/issues/211515
-  describe.skip('data_streams_list', () => {
+  describe('data_streams_list', () => {
     skipIfNoDockerRegistry(providerContext);
 
     beforeEach(async () => {