Soul speed no longer works through partial blocks

The bug

Prior to 24w18a, the soul speed effect would work through partial blocks such as carpets and slabs. However, in 24w18a, this is no longer the case. Further, if you use soul sand, the soul sand slowness effect applies, but the soul speed affect does not apply, which makes no sense.

Steps to reproduce

1. Place some soul sand.
2. Place carpets on the soul sand
3. Wear soul speed 3 boots
4. Walk on the soul sand

Observed result

The soul speed is completely ignored

Expected result

Soul speed would function as it did previously through carpets and other partial blocks