try aliasing pacstrap to pacstrap -N for unshare mode, maybe

.woodpecker.yaml

@@ -7,8 +7,8 @@ steps:
     image: docker.io/archlinux:base-devel
     privileged: true
     commands: 
-      - mkdir -p /tmp/boop && mount -t devtempfs dev /tmp/boop || sleep 300
       - pacman -Sy
+      - alias pacstrap="pacstrap -N"
       - ./build-iso
       - eval $(grep iso_ archiso/profiledef.sh)
       - ISO_FILE="archiso/out/$iso_name-$iso_version-x86_64.iso"