locale switcher: switching to `get_locale` is useless

[yoavf]

With the introduction of the locale switcher in [38961], we've implemented 3 core switches that use get_locale() as the locale argument:

switch_to_locale( get_locale() );

delete site email
wp_notify_postauthor
wp_new_user_notification

Switching to get_locale() is useless because locale gets filtered by the locale switcher, which will use the last locale switched to as the return value. So we're just switching to the current locale (if no locale switch has ever happened) or to the current locale again if we did switch.

[yoavf]

Test demonstrating the issue

[ocean90]

Why should it be useless if a user locale is X but the site locale is Y? How would you make sure that the emails are sent in the language of the site?

[yoavf]

Bah, you're right! I was missing something while testing here, the test actually passes with current code. Sorry!