The step_height attribute of nautili is only 0.6 despite them behaving as if it were 1.0

As far as gameplay is concerned, nautili seemingly have a step_height base value of 1.0, which is good because if it were any less it would be all too easy for the player to strand their nautilus in a location where it could not get back into the water, leading to its quick demise. However, inspecting the attribute reveals that it is in fact only 0.6, and further testing reveals that nautili always behave as if their step_height were no less than 1.0. I can’t think of a reason to hardcode this particular behavior, especially considering MC-268917 was WAI’d despite the obvious negative effects on gameplay. Removing this special handling would make things work more intuitively and allow for greater customization (for example, a tiny nautilus which cannot step up blocks because it is too small).

To reproduce

1. Ride a nautilus along the ground or ocean floor until it collides with an obstacle which is surmountable by mobs with a step_height attribute of 1, i.e. a full block
   ✅ The nautilus steps onto the block

2. /execute on vehicle run attribute @s minecraft:step_height get
   ❌ The nautilus' step height is only 0.6, so it is unclear why it was able to step onto the block

Expected result

The nautilus would have a step_height of 1.0.