Nether portals disregard their hitbox when teleporting entities

Relates to MC-215402 and MC-262309. Nether portals teleport entities regardless of whether their hitbox intersects with the portal's hitbox. However, end portals do not exhibit this behavior. The portal consistently behaves as if it were a full block. This may be an intentional design choice.

Steps to reproduce

1. /execute align xyz run tp ~ ~ ~

2. Go into survival mode

3. /setblock ~ ~ ~ minecraft:nether_portal

Observed outcome: The nether portal teleports you even though your hitbox doesn't intersect with it.
Expected outcome: If your hitbox doesn't intersect with the portal's hitbox, it shouldn't teleport you.