Nobody makes cluster bombs in the US by the way.

This is somewhere between disingenuous and flat-out wrong.

Textron is a USA firm that produces Sensor Fuzed Weapons (SFW). The SFW is a cluster munition that is prohibited by the Convention on Cluster Munitions. The USA's Air Force has been the primary buyer of these until about 2016. Although it seems direct sales of cluster munitions halted around 2016 when the moratorium on cluster munitions was put in to place, this firm is still responsible for maintenance (which they are paid for) of existing munitions. (You'll note as well that "stockpiling and/or retention of cluster munitions" is also against the Convention on Cluster Munitions, not just the manufacture and use of them).

Orbital ATK (operating as Northrop Grumman Innovation Systems since its acquisition by defense contractor Northrop Grumman in 2018), a USA defense contractor, previously produced key components of the Textron weapons mentioned above. Although they no longer produce these parts for these purposes directly, they still have ongoing tangential contracts.

Moreover, these cluster munitions that are going to be sent are filled with M42/M46 grenades, which from what I can tell are manufactured by USA-based defense firms. The shells, which include the M1122, are coming from recycled munitions, so they aren't being manufactured new; but: they were produced by USA-based defense firms originally, and their consumption motivates replacement which also happens by USA-based defense firms.

Also, the notorious defense firms Lockheed Martin and Alliant Techsystems are helping develop the next generation of cluster munitions; so, increased use of the existing generation will almost certainly cause increased spending on future generations of the same type of weapon.