Remove tripleo-multinode-container-minimal from zuul layout

The tripleo-multinode-container-minimal is being deprecated [1]
as part of wider tripleo CI optimization at [2].

[1] Ie6473759383bd4b903cbe56fba9fee75a24154c4
[2] https://review.opendev.org/q/topic:tripleo-ci-reduce

Change-Id: Ie28dd59a6bec79802d149f030f10a2ea12e454de

zuul.d/layout.yaml

@@ -3,4 +3,3 @@
       - check-requirements
       - openstack-cover-jobs
       - openstack-python3-victoria-jobs
-      - tripleo-multinode-container-minimal