Summary:
Prior to 24w05a, llamas and trader llamas would drop equipped carpets upon death, regardless of the gamerule doMobLoot setting. However, as of 24w05a, this behavior has ceased due to alterations in how the carpet is stored.

Steps to reproduce:

1. /gamerule doMobLoot false

2. /summon llama ~ ~ ~ {Health:1f,Tame:1b,body_armor_item:{id:"minecraft:red_carpet",count:1}}

3. Kill the llama.

4. /summon minecraft:trader_llama ~ ~ ~ {Health:1f,Tame:1b,body_armor_item:{id:"minecraft:red_carpet",count:1}}

5. Kill the trader llama.

Observed result:
Llamas and trader llamas do not drop their carpet when the gamerule doMobLoot is false.

Expected result:
Llamas and trader llamas should drop their carpet even when the gamerule doMobLoot is set to false, as was the case before 24w05a.

Video:
llamas doMobLoot false 24w04a.mp4
llamas doMobLoot false 1.20.6.mp4