DEVELOPERS: drop Arthur Courtel

450 4.1.1 <arthur.courtel@smile.fr>: Recipient address rejected: User
unknown in virtual mailbox table

Arthur is no longer at Smile.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

DEVELOPERS

@@ -229,10 +229,6 @@ F:	package/python-bottle/
 F:	package/sqlcipher/
 F:	package/stress/
 
-N:	Arthur Courtel <arthur.courtel@smile.fr>
-F:	board/raspberrypi/genimage-raspberrypi4-64.cfg
-F:	configs/raspberrypi4_64_defconfig
-
 N:	Asaf Kahlon <asafka7@gmail.com>
 F:	package/collectd/
 F:	package/libfuse3/