@Sirchristopher10 btw can you get those from skeles?
There's a rare chance that trapped skeletons will spawn with a helmet or a bow with conflicting enchantments (e.g. Punch 1 and 2 on a bow, two Protection 3 enchantments on a helmet,) due to an oversight on Mojang's part.
Therefore, it could be possible for a trapped skeleton to drop a Mending Infinity bow in this way. However, Mending is a treasure enchantment, so it can only be acquired from dungeon looting, trading, or fishing. There's a 0% chance of Mending appearing on a skeleton's bow, so you're out of luck.