sonic-yang-models: add dependency on libyang3-py3 (unused)

We need to force libyang3-py3 to be built and tested, and confirm
it can properly co-exist with libyang1 and its python bindings.

Its currently not used, but will be in a followup.

Author: bradh352

rules/sonic-yang-models-py3.mk

@@ -2,7 +2,9 @@ SONIC_YANG_MODELS_PY3 = sonic_yang_models-1.0-py3-none-any.whl
 $(SONIC_YANG_MODELS_PY3)_SRC_PATH = $(SRC_PATH)/sonic-yang-models
 $(SONIC_YANG_MODELS_PY3)_PYTHON_VERSION = 3
 $(SONIC_YANG_MODELS_PY3)_DEBS_DEPENDS = $(LIBYANG) $(LIBYANG_CPP) \
-                                        $(LIBYANG_PY3)
+                                        $(LIBYANG_PY3) \
+                                        $(LIBYANG3) \
+                                        $(LIBYANG3_PY3)
 
 SONIC_PYTHON_WHEELS += $(SONIC_YANG_MODELS_PY3)
 export SONIC_YANG_MODELS_PY3