CI: get rid of snap and speed up CI (#13938)

Signed-off-by: Philip H <47042125+pheiduck@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

ci/remove_snap.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env sh
+pushd /etc/apt/preferences.d/
+cat > nosnap.pref <<EOF
+# To prevent repository packages from triggering the installation of snap,
+# this file forbids snapd from being installed by APT.
+
+Package: snapd
+Pin: release a=*
+Pin-Priority: -10
+EOF
+popd
+snap remove --purge $(snap list | awk '!/^Name|^core/ {print $1}')
+apt-get purge -y snapd