did the ancient egyptians make the kopesh out of iron or steel at any point,

Yes.

or was it only used and produced during the bronze age?

The khopesh (and similar swords in the Levant) fell out of use in the late Bronze Age, and the style wasn't revived in the Iron Age.

There are some iron weapons that were contemporary with the khopesh, such as the meteoric iron dagger from Tutankhamun's coffin. In principle, a meteoric iron khopesh could have been made, but it would have been stupendously expensive (and not performed any better as a weapon).

when i look at reproductions, i see both bronze and steel

Some of the bronze reproductions are quite accurate. Generally, the steel reproductions are only vaguely khopesh-shaped, and don't replicate the geometry of a real khopesh. This kind of thing is commonly the case when there are bronze and steel modern reproductions of Bronze Age weapons - this is because casting allows bronze weapons to have complex geometries relatively easily, but producing such complex geometries in steel would require either extensive milling or tricky forging (or machine forging with a lot of tooling) which would make such steel reproductions much more expensive than accurate bronze reproductions.