Use US spelling of 'behavior'

Marlin/Configuration_adv.h

Marlin/src/feature/bltouch.cpp

Marlin/src/gcode/bedlevel/G26.cpp

Marlin/src/gcode/config/M301.cpp

Marlin/src/gcode/control/M999.cpp

Marlin/src/module/thermistor/thermistor_20.h

config/default/Configuration_adv.h

config/examples/3DFabXYZ/Migbot/Configuration_adv.h

config/examples/AlephObjects/TAZ4/Configuration_adv.h

config/examples/AliExpress/UM2pExt/Configuration_adv.h

config/examples/Anet/A2/Configuration_adv.h

config/examples/Anet/A2plus/Configuration_adv.h

config/examples/Anet/A6/Configuration_adv.h

config/examples/Anet/A8/Configuration_adv.h

config/examples/Anet/A8plus/Configuration_adv.h

config/examples/Anet/E16/Configuration_adv.h

config/examples/AnyCubic/i3/Configuration_adv.h

config/examples/ArmEd/Configuration_adv.h

config/examples/BIBO/TouchX/cyclops/Configuration_adv.h

config/examples/BIBO/TouchX/default/Configuration_adv.h