In short, the Fire aspect enchantment doesn't break the tools when it is low on durability.

Steps to Reproduce

1. Give yourself a sword with low durability:

   /give @s minecraft:netherite_sword[minecraft:damage=2030]
   

2. Place down some campfire, put it out using a shovel
3. Place down some candles
4. Enchant the sword with fire aspect enchantment
5. Change to survival mode (since you cannot light it up in creative)
6. Light up the campfire/candles
7. Pay attention to the sword

Expected Result
The sword should've break after being used.

Observed Result
The sword didn't break at all in durability.