Steps to reproduce:

1. Create a void world with the provided data pack.
2. Use the following commands to create and display a scoreboard:

   /scoreboard objectives add Health dummy "Health"
   /scoreboard objectives setdisplay sidebar Health

3. Place an always active repeating command block with the following command:

   execute as @p at @s as @n[type=!minecraft:player] store result score @s Health run data get entity @s Health 1000000

4. Spawn some mob in a cage: the scoreboard will display its health with a precision of 1 millionth.
5. Enchant a weapon with the squeaky:squeaky enchantment, which multiplies the weapon's damage by 0, resulting in a weapon dealing 0 damage.
6. Hit the mob, multiple times to ensure the enchantment's behavior: its health will not change as expected.
7. Hit the mob faster, at least faster than one hit every 400ms for a sword from what I noticed, if possible with an auto-clicker to get a consistant timing but simply spamming also does the trick.

Observed result:
The mob will sometimes take a very small amount of damage, less than 0.1 HP.

Expected result:
The mob does not take damage.