Fix arch installs as 8.1 is unavailable and #5456 has been merged (#5857)

util/linux_install.sh

@@ -54,8 +54,7 @@ elif grep ID /etc/os-release | grep -qE 'debian|ubuntu'; then
 		zip
 
 elif grep ID /etc/os-release | grep -q 'arch\|manjaro'; then
-	# install avr-gcc 8.1 until 8.3 is available. See #3657 for details of the bug.
+	sudo pacman -U https://archive.archlinux.org/packages/a/avr-gcc/avr-gcc-8.3.0-1-x86_64.pkg.tar.xz
-	sudo pacman -U https://archive.archlinux.org/packages/a/avr-gcc/avr-gcc-8.1.0-1-x86_64.pkg.tar.xz
 	sudo pacman -S \
 		arm-none-eabi-binutils \
 		arm-none-eabi-gcc \