As a NATO member, that is a commitment to help Ukraine.
No doubt about that.
But things have changed. Now Ukraine wants to attack Russia.
So the problem is: will Italy help Ukraine attack and besiege Russia? I doubt that.
You just changed your question. Your original question was only about sending weapons to ukraine, period.
Many countries that are sending weapons to ukraine, do so with the explicit condition that they can only be used to defend ukraine on ukrainian territory. In fact, that was the case for pretty much all weapons from all countries, until quite recently.
I wouldn't know what Italy's stance is on that one without looking it up.
But as I said: there is nothing in the public record which suggests they will stop sending weapons / supporting Ukraine in their defense against an invading aggressor.
EDIT: so I looked it up and idd, Italy's stance on using its weapons to strike at Russia itself remains unchanged. This has been so since the beginning so it's not like this is a new development or a change in policy regarding Italy's help to Ukraine, like you seem to be insinuating. Things have not changed.
Additionally, Italy is sending another Samp-T battery. So it is in fact actively in the process of sending weapons.
EDIT2: officially, only 13 countries have given Ukraine permission to use weapons supplied by them inside Russia. These countries are France, UK, Poland, Lithuania, Latvia, Estonia, Netherlands, Sweden, the Czech Republic, Finland, Denmark, Norway and Canada.
Note how the US isn't one of them. Restrictions by the US have been relaxed since may 31, but officially Ukraine can't use, for example, long range missiles to hit Russia.
So why you are making such a big deal concerning Italy's stance on Ukraine not using Italian weapons in Russia, is kind of a mystery.