/damage only allows integers even though damage can be fractional now

From the 1.18.20.27 changelog:

Damage is now calculated more accurately, we now properly calculate and store partial damage for larger damage

This ostensibly brings Bedrock into parity with the changes Java made back in 2013. However, /damage still can't do partial damage.

/damage @p 0.5

Expected behavior
You take a quarter-heart of damage

Actual behavior
Syntax error