fixed GKE timeout flakiness

[IsaSih]

Summary

Fixes #rancher/qa-tasks#2318

Occurred changes and/or fixed issues

Fixing timeout flakiness in GKE test: AssertionError: Timed out retrying after 10000ms: Expected to find element: [data-testid="side-menu"], but never found it.
Changed ClusterManagerListPagePo.navTo(); to goTo() to avoid non-relevant UI navigation and instead navigate straight to the page. Also, another loadingPo.checkNotExists(); to make sure the cloud cred form is fully rendered before proceeding with the test.

Areas or cases that should be tested

gke-cluster-provisioning.spec.ts

Areas which could experience regressions

Low impact changes to cause regressions elsewhere

Screenshot/Video

Checklist

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[izaac]

Looks good, let's take a minute to add qase()

[izaac]

Additional to my review I see your dsescription screenshot is using a local run, can we either test on Jenkins or using the playbook locally instead?