Add --csp.warnLegacyBrowsers=false to cypress

[Hailong-am]

Is your feature request related to a problem?

when doing functional test, there has a csp warning toast in the bottom right of the page that will cover the bottom bar. when click on the button that will need to add { force: true } option for click method.

What solution would you like?

Add ignore csp waring for cypress test, similar with https://github.com/opensearch-project/OpenSearch-Dashboards/blob/460428cdfd9bd1bdb7e074b81c9779e1e84c1166/.github/workflows/cypress_workflow.yml#L33

What alternatives have you considered?

A clear and concise description of any alternative solutions or features you've considered.

Do you have any additional context?

Add any other context or screenshots about the feature request here.

[derek-ho]

👍