damage_ring: Remove wlr_damage_ring_set_bounds

This wasn't that great:

1. Now that damage ring tracks damage across actual wlr_buffer objects, it can use the buffer size to do any sort of cropping that needs to happen.
2. The damage ring size really should be the size of the transformed size of the output. Compositors currently have to call wlr_damage_ring_set_bounds() where it might not be clear when to call the function. Compositors can just check against the actual output bounds that they care about when processing the damage.

Fixes: #3891 (closed)

breaking:

• wlr_damage_ring.{width, height} are removed
• wlr_damage_ring_set_bounds() is removed
• The return value of wlr_damage_ring_add{,_box}() is removed. Compositors can just crop with the actual output coordinates.