Would Crabominable's "Food Prep" Ability reduce the attack cost of cards like Technical Machine:Crisis Punch?
Yes, any attack used by Crabominable would have its attack cost reduced for each Kofu in your discard pile.
Source: Stellar Crown FAQ; TPCi Rules Team (2024-09-12)

Relevant cards

Note: All applicable cards may not be listed below.
SV7_42
SV7_42
SV7_138
SV7_138
SV45_90
SV45_90