In Firefox, it’s impossible to select and copy the public key that is shown in Admin - Customize - Themes - Import - From the Web - “Theme is in a private git repository”
You cannot select the text from the textarea when the disabled attribute is set in Firefox.
AFAIK, the readonly attribute should be used here instead of disabled.
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/textarea:
readonlyThis Boolean attribute indicates that the user cannot modify the value of the control. Unlike the
disabledattribute, thereadonlyattribute does not prevent the user from clicking or selecting in the control. The value of a read-only control is still submitted with the form.
