Added flash_mode=dio to avoid boot loop when flashing using merge.bin

Author: IoTThinks

variants/xiao_c6/platformio.ini

@@ -1,6 +1,7 @@
 [Xiao_C6]
 extends = esp32c6_base
 board = esp32-c6-devkitm-1
+board_build.flash_mode = dio
 board_build.partitions = min_spiffs.csv ; get around 4mb flash limit
 build_flags =
   ${esp32c6_base.build_flags}