[build]: Remove "rules/python3.dep" (#4762)

Signed-off-by: Joyas Joseph <joyas_joseph@dell.com>

rules/python3.dep

@@ -1,10 +0,0 @@
-
-SPATH       := $($(LIBPY3_MIN)_SRC_PATH)
-DEP_FILES   := $(SONIC_COMMON_FILES_LIST) rules/python3.mk rules/python3.dep   
-DEP_FILES   += $(SONIC_COMMON_BASE_FILES_LIST)
-DEP_FILES   += $(shell git ls-files $(SPATH))
-
-$(LIBPY3_MIN)_CACHE_MODE  := GIT_CONTENT_SHA 
-$(LIBPY3_MIN)_DEP_FLAGS   := $(SONIC_COMMON_FLAGS_LIST)
-$(LIBPY3_MIN)_DEP_FILES   := $(DEP_FILES)
-