On the user's preference, change the timezone to one that is different
from the browser.
Save the form.
Go back to the user's preferences.
Before this commit, every timezone was displayed inside the span that contain
the warning icon, and leaked everywhere on the form view.
This was because of the joint action effects of commits:
86897ca1674dfabb8f7a
Which provoked the field to be re-rendered in edit mode,
but with an $el on which a span was added. `<option/>` elements
were then added to both `<select>` and `<span>`
This did not happen before v12.0
After this commit, there is no display glitch
OPW 1895088
closesodoo/odoo#28108
Lucas Perais (lpe)
eaedfe4074