[Core] Remove PROGRAM_CMD in mcu_selection.mk for 32A (#7482)

quantum/mcu_selection.mk

@@ -87,9 +87,6 @@ ifneq (,$(filter $(MCU),atmega32a))
   # unsupported features for now
   NO_UART ?= yes
   NO_SUSPEND_POWER_DOWN ?= yes
-
-  # Programming options
-  PROGRAM_CMD ?= ./util/atmega32a_program.py $(TARGET).hex
 endif
 
 ifneq (,$(filter $(MCU),atmega328p))