Drywall – Should I hang drywall up to the ceiling (using steel studs)

I'm not sure it would be worth making any stud that couldn't take drywall. For walls, the drywall creates an axial load on the stud which it should easily support. But interior walls must also support an arbitrary lateral load, 5 psf in the US. This combined with the axial load is what would do it in. The manufacturer of the studs should publish span tables that tell you the maximum height wall for which you can use each style of stud under varying conditions.

I've little doubt you can find a 2.5" stud that works, but I'm not sure the proper gauge. That's where the span tables come in. Sorry I can't give you a final answer. All I can say is there's reason for hope.

Even though you found the stud with your stud finder, you may have missed it. Even steel studs will offer a bit of resistance to drilling, and you should see some metal filings or twists following the bit out of the wall. You may have to try again with a very small bit 3/4 inch one way or the other to find the stud. Use your stud finder to give yourself a better idea what side of the original hole you should try. Of course, you can use the hole you already drilled by inserting a drywall anchor rated for the load you want to attach. I prefer the corkscrew type anchors to the expansion type.

There is a difference between the interior private walls and the common wall in condos. Common walls are always thicker, usually thicker sheetrock or two layers of 1/2 inch rock. This is for a longer fire time rating and soundproofing between units.