[fix] : fix GnuPG home directory permissions

Author: Hayao0819

system/initcpio/install/archiso

@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
 
 build() {
     add_module "cdrom"
@@ -22,7 +24,7 @@ build() {
     add_file /usr/lib/udev/rules.d/95-dm-notify.rules
     add_file /usr/lib/initcpio/udev/11-dm-initramfs.rules /usr/lib/udev/rules.d/11-dm-initramfs.rules
     if [[ $ARCHISO_GNUPG_FD ]]; then
-        mkdir -p "$BUILDROOT/gpg"
+        mkdir -m 0700 -- "$BUILDROOT/gpg"
         gpg --homedir "$BUILDROOT/gpg" --import <& "$ARCHISO_GNUPG_FD"
     fi
-}
+}