villagers spawned by a spawner don't pick up food (1.21.8)

This issue is Invalid. Assuming you grabbed a spawner from the creative inventory, it is summoning villagers in a default state where they cannot pick up items.
Using this command; /give @p spawner[block_entity_data={id:"mob_spawner",SpawnData:{entity:{id:"minecraft:villager",CanPickUpLoot:1b}}}] 1 will give you a spawner that summons villagers which can pick up items.