Migrate build target markers to keyboard.json - Misc (#23609)

keyboards/matrix/noah/keyboard.json

@@ -83,6 +83,8 @@
     "rgblight": true,
     "rgb_matrix": true
   },
+  "processor": "STM32F411",
+  "bootloader": "custom",
   "community_layouts": ["65_iso_blocker"],
   "layouts": {
     "LAYOUT_default": {

keyboards/matrix/noah/rules.mk

@@ -1,18 +1,7 @@
-# MCU name
-MCU = STM32F411
-
-# Linker script to use
-# - it should exist either in <chibios>/os/common/ports/ARMCMx/compilers/GCC/ld/
-#   or <this_dir>/ld/
+# custom bootloader
 MCU_LDSCRIPT = noah_boot
-
-# Board: it should exist either in <chibios>/os/hal/boards/
-#  or <this_dir>/boards
 BOARD = ST_NUCLEO64_F411RE
 
-# Bootloader selection
-BOOTLOADER = custom
-
 WS2812_DRIVER_REQUIRED = yes
 
 CUSTOM_MATRIX = yes