switch find-bootloader-path over to using arduino prefs, killing our last internal use of BOARD_HARDWARE_PATH

bin/kaleidoscope-builder

@@ -378,9 +378,7 @@ flash_with_programmer() {
 }
 
 find_bootloader_path() {
-    BOOTLOADER_FILE=$( get_arduino_pref 'bootloader.file' )
-    : "${BOOTLOADER_FILE:=caterina/Caterina.hex}"
-    : "${BOOTLOADER_PATH:=${BOARD_HARDWARE_PATH}/keyboardio/avr/bootloaders/${BOOTLOADER_FILE}}"
+    : "${BOOTLOADER_PATH:=$( get_arduino_pref 'runtime.platform.path' )/bootloaders/$( get_arduino_pref 'bootloader.file' )}"
 }
 
 

etc/kaleidoscope-builder.conf

@@ -202,10 +202,3 @@ COMPILER_PREFIX="${COMPILER_PREFIX-avr-}"
 
 : "${AVRDUDE:=${ARDUINO_TOOLS_PATH}/avr/bin/avrdude}"
 : "${AVRDUDE_CONF:=${ARDUINO_TOOLS_PATH}/avr/etc/avrdude.conf}"
-
-######
-###### Source files and dependencies
-######
-
-: "${BOARD_HARDWARE_PATH:=${ARDUINO_LOCAL_LIB_PATH}/hardware}"
-