This commit rephrases the `DefaultTransactionDefinition#setTimeout`
exception message to better reflect the fact that 0 is a valid input
value.
Even though this often leads to a transaction immediately timing out
after opening, there is one notable case where this has another
meaningful effect: in Jakarta transactions (`UserTransaction`), when
passing 0 "the transaction service restores the default value".
Closes gh-32635
8ec27438e7