Use the default source origin for mysql & rabbit

The functional test bundles specify that the mysql and rabbit
services should use the openstack-origin reference field, but this
is not actually relevant to the rabbit/mysql charms (e.g. it doesn't
make sense to install rabbit from cloud:jammy-zed as rabbit is from
the distro).

Change-Id: I50693d6e85b2ce427ff184555cdfae66096f3f6c

src/tests/bundles/jammy-zed.yaml

@@ -35,8 +35,6 @@ applications:
   mysql-innodb-cluster:
     charm: ch:mysql-innodb-cluster
     num_units: 3
-    options:
-      source: *openstack-origin
     to:
       - '0'
       - '1'
@@ -46,8 +44,6 @@ applications:
   rabbitmq-server:
     charm: ch:rabbitmq-server
     num_units: 1
-    options:
-      source: *openstack-origin
     to:
     - '3'
     channel: latest/edge

src/tests/bundles/kinetic-zed.yaml

@@ -35,8 +35,6 @@ applications:
   mysql-innodb-cluster:
     charm: ch:mysql-innodb-cluster
     num_units: 3
-    options:
-      source: *openstack-origin
     to:
       - '0'
       - '1'
@@ -46,8 +44,6 @@ applications:
   rabbitmq-server:
     charm: ch:rabbitmq-server
     num_units: 1
-    options:
-      source: *openstack-origin
     to:
     - '3'
     channel: latest/edge