Cross-dimensional @s selector succeeds despite world-binding parameters

The bug

World-binding selector arguments x y z dx dy dz distance will restrict selector results to entities in the dimension the command context is executing from. However @s is not restricted, and it will be found regardless of the presence of world-binding arguments if the sender dimension differs from the context dimension.

How to reproduce

1. Enter the overworld.
2. /execute in the_nether unless entity @a[x=0]
   →   Test passed
3. /execute in the_nether unless entity @s[x=0]
   →   Test failed, count: 1