Avoid 3 known debconf prompts during deployment.

Even if those prompts and the associated answers are already documented
in “Beginner guide - How to setup a PiRogue”, it's a bit annoying to
have to go through them every time a new PiRogue is set up.

Let's pick the right answers (moving away from the default every time),
and mark those questions as seen (i.e. asked and answered):

 - Save current IPv4 rules?                           Yes → No
 - Save current IPv6 rules?                           Yes → No
 - Should non-superusers be able to capture packets?  No → Yes

Link: https://github.com/PiRogueToolSuite/pirogue-images/issues/3

raspberrypi/recipes/pi3-pi4.sh

@@ -33,4 +33,8 @@ toast_me() {
   # Add PTS PPA
   chroot $MNT wget -O /etc/apt/sources.list.d/pirogue.list https://pts-project.org/debian-12/pirogue.list
   chroot $MNT wget -O /etc/apt/trusted.gpg.d/pirogue.asc   https://pts-project.org/debian-12/Key.gpg
+
+  # Make initial installation easier on users:
+  install -m 755 -o root -g root files/avoid-debconf-prompts $MNT/root/avoid-debconf-prompts
+  chroot $MNT /root/avoid-debconf-prompts && rm -f $MNT/root/avoid-debconf-prompts
 }

raspberrypi/recipes/pi5.sh

@@ -34,6 +34,10 @@ toast_me() {
   chroot $MNT wget -O /etc/apt/sources.list.d/pirogue.list https://pts-project.org/debian-12/pirogue.list
   chroot $MNT wget -O /etc/apt/trusted.gpg.d/pirogue.asc   https://pts-project.org/debian-12/Key.gpg
 
+  # Make initial installation easier on users:
+  install -m 755 -o root -g root files/avoid-debconf-prompts $MNT/root/avoid-debconf-prompts
+  chroot $MNT /root/avoid-debconf-prompts && rm -f $MNT/root/avoid-debconf-prompts
+
   ### BEGIN: Pi 5 section
 
   # Preconfigure raspi-firmware to disable the default cma= setting on the