[continuous-integration] fix test_dua_routing.py (#7117)

Added new API/CLI for reference devices to set allowed ranges of
router IDs. When the allowed ID range is set, the leader will only
assign router IDs in the range. In this way, we can assign
non-overlapping router ID ranges to different thread networks so that
no RLOC16s will collide across multiple thread networks.

tests/scripts/thread-cert/backbone/test_dua_routing.py

@@ -70,6 +70,7 @@ class TestNdProxy(thread_cert.TestCase):
             'is_otbr': True,
             'version': '1.2',
             'channel': CH1,
+            'router_id_range': [0, 30],
         },
         SBBR: {
             'name': 'SBBR',
@@ -93,6 +94,7 @@ class TestNdProxy(thread_cert.TestCase):
             'is_otbr': True,
             'version': '1.2',
             'channel': CH2,
+            'router_id_range': [31, 60],
         },
         ROUTER2: {
             'name': 'ROUTER2',