ACX/PTX EVO routers do not support MPLS families on IRB

Device running EVO with 'family mpls' set under the IRB:

set interfaces irb mtu 1650
set interfaces irb unit 1001 traps
set interfaces irb unit 1001 family inet address 192.168.0.132/31
set interfaces irb unit 1001 family mpls

Does not forward MPLS frames
 

ACX/PTX EVO routers do not support MPLS families on IRB.  External documentation:

https://www.juniper.net/documentation/us/en/software/junos/bridging-learning/topics/task/layer-2-services-bridge-domains-configuring-irb-for-acx-series.html#:~:text=ACX%20routers%20do%20not%20support%20MPLS%20families%20on%20IRB.

Note that PR1763785 adds support for a commit error to avoid any confusion:

https://prsearch.juniper.net/PR1763785