build(e2e): Cypress GH Action wait-on in sync with baseUrl

[davidlj95]

Seems if we don't set wait-on, no wait will occur (at least by GH Action code):

https://github.com/cypress-io/github-action/blob/v6.6.1/index.js#L421-L424

And if specifying a URL in there, we're specifying same URL as in baseUrl config. So this value has to be in sync :(

Could be good if there was some way to say: wait on base URL. So that value is the source of truth.

[davidlj95]

Done in #569