[A11y] [VPAT] 2.4.3 Focus Order - Focus order is not contained within side panel

[dave-gus]

Steps to Reproduce:

Create a Search project and go to the Search project homepage (ex: https://my-elasticsearch-project-eca3d1.kb.eu-west-1.aws.qa.elastic.cloud/app/elasticsearch)

In left nav, select 'Playground'
Under 'Connect to LLM', select 'Connect'
Keyboard focus is now in the side panel which has opened. Tab through the side panel

The issue:
Keyboard focus leaves the side panel and goes to the top of the page and progresses through the greyed-out left nav and the top nav before returning to the side panel. Keyboard focus order should be contained within the side panel until it is closed.

WCAG or Vendor Guidance (optional)

• Understanding SC 2.4.3 Focus Order (Level A)

[daveyholler]

@radhapolisetty I've added this to the Search Experiences team project

[yansavitski]

@daveyholler Created a bug for EUI team as flyout focus was broken after updating navigation in Kibana and ES3, with new EuiCollabsableNavBeta

[yansavitski]

Should be fixed here