weston-launch: Provide a default version that doesn't require PAM

weston-launch requires PAM for starting weston as a non-root user.

Since starting weston as root is a valid use case by itself, if
PAM is not available, provide a default version of weston-launch
without non-root-user support.

Signed-off-by: Tom Hochstein <tom.hochstein@nxp.com>
Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Signed-off-by: Randy 'ayaka' Li <ayaka@soulik.info>
2 jobs for review_pam in 6 minutes and 35 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #197599
build-native-autotools

00:06:35

passed #197600
build-native-meson

00:02:07