delete_expired_transients() does not delete expired transient created with a false/empty transient name

[jeremyescott]

Due to a typo/bug in my plugin code, I found that WordPress accepts empty strings, null, and false for the $transient arg, aka: the transient name, in set_transient() function which creates transients in the options database with values of simply _transient_ and _transient_timeout_.

The empty string transient is not be cleaned up by the delete_expired_transients() routine.

Related is patch #58903, though I do not feel comfortable making a patch for this issue as the fix requires has SQL calls.