CI: arch: do not package up source files for stepping through code with gdb

makepkg can do this, if when building packages from source you enable
debug. This is apparently being shipped in the /etc/makepkg.conf in
docker containers, which means building AUR packages now requires
installing debugedit, and then bloating your container with
/usr/src/debug. We really do not want that.

Reconfigure so that we do not, in fact, need that.

ci/ciimage/arch/install.sh

@@ -41,6 +41,9 @@ useradd -m $AUR_USER
 echo "${AUR_USER}:" | chpasswd -e
 echo "$AUR_USER      ALL = NOPASSWD: ALL" >> /etc/sudoers
 
+# fix installing packages from source, attempting to install debug info
+sed -i '/OPTIONS/{s|debug|!debug|}' /etc/makepkg.conf
+
 # Install yay
 su $AUR_USER -c 'cd; git clone https://aur.archlinux.org/yay.git'
 su $AUR_USER -c 'cd; cd yay; makepkg'