Remove direct branching rights for murano-apps
Remove direct branching rights for murano-apps

Branching now goes through requests to openstack/releases,
so that it can be properly tested before the branch is created.
Murano-apps never created a branch, but in case future branches
are needed, those would go through openstack/releases changes.

Change-Id: I7fa5d9b6618288412ba435a4e07a7d4d89f15e6a

openstack-infra/project-config,openstack-infra/project-config