[ML] Single Metric viewer: ensure ml node check is consistent and remove flaky test skip

[alvarezmelissa87]

Summary

Related skipped tests: #189537 and #189565

Removed the skipped tests.

Updated the node check for forecasting to be as it was before the change introduced in #188791

Before that change, the forecasting modal only checked node count and did not check lazy node count. That PR added a check for node count.

In this PR, the node count check is going back to what it was prior.

Flaky test runner build: https://buildkite.com/elastic/kibana-flaky-test-suite-runner/builds/6657

Checklist

Delete any items that are not applicable to this PR.

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• Flaky Test Runner was used on any tests changed
• Any UI touched in this PR is usable by keyboard only (learn more about keyboard accessibility)
• Any UI touched in this PR does not create any new axe failures (run axe in browser: FF, Chrome)
• If a plugin configuration key changed, check if it needs to be allowlisted in the cloud and added to the docker list
• This renders correctly on smaller devices using a responsive layout. (You can test this in your browser)
• This was checked for cross-browser compatibility

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[kibanamachine]

Flaky Test Runner Stats

🟠 Some tests failed. - kibana-flaky-test-suite-runner#6657

[❌] x-pack/test/functional/apps/ml/permissions/config.ts: 2/30 tests passed.

see run history

[alvarezmelissa87]

@elasticmachine merge upstream

[kibana-ci]

💔 Build Failed

• Buildkite Build
• Commit: dd8cae8
• Interpreting CI Failures

Failed CI Steps

• FTR Configs #56
• FTR Configs #56

Test Failures

• [job] [logs] FTR Configs #56 / aiops log rate analysis with 'kibana_sample_data_logstsdb' kibana sample data logs displays index details
• [job] [logs] FTR Configs #56 / aiops log rate analysis with 'kibana_sample_data_logstsdb' kibana sample data logs displays index details

Metrics [docs]

Async chunks

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

id	before	after	diff
ml	4.6MB	4.6MB	-46.0B

History

• 💛 Build #225135 was flaky 1b5a532

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

cc @alvarezmelissa87