Test for clipboard usage in Secrets e2e tests

[joelfried]

The secrets end to end tests should test to make sure that the copy to clipboard functionality works properly. Unfortunately due to an issue in Cypress we can't test the contents of the clipboard properly and attempting to do so causes the tests to fail.

Specifically the fallback method used by React Copy to Clipboard causes an alert to be opened inside Cypress that it won't autodismiss with a success (it looks like this:

)

This is a known issue with Cypress being tracked here - once that issue is resolved and we've updated to the appropriate version of Cypress, uncommenting the relevant lines in secrets.test.ts should just work (in theory).