libpam: ccmp13: disable pam_systemd integration to improve login performance

On the CCMP13 platform, the inclusion of pam_systemd in the PAM stack
causes excessive delays during login -close to 10 seconds- and can
even lead to SSH login failures.
Since we do not require per-user systemd services (--user), disable
the pam_systemd session module to improve login responsiveness.

Signed-off-by: Isaac Hermida <isaac.hermida@digi.com>

meta-digi-dey/recipes-extended/pam/libpam_%.bbappend

@@ -0,0 +1,5 @@
+# Copyright (C) 2025, Digi International Inc.
+
+do_install:append:ccmp13() {
+	sed -i '/pam_systemd.so/d' ${D}${sysconfdir}/pam.d/common-session
+}