Build: move "make update" on macOS and Linux to Python script

Differential Revision: https://developer.blender.org/D5545

GNUmakefile

@@ -531,17 +531,7 @@ icons_geom: .FORCE
 	    "$(BLENDER_DIR)/release/datafiles/blender_icons_geom_update.py"
 
 update: .FORCE
-	if [ "$(OS_NCASE)" = "darwin" ] && [ ! -d "../lib/$(OS_NCASE)" ]; then \
-		svn checkout https://svn.blender.org/svnroot/bf-blender/trunk/lib/$(OS_NCASE) ../lib/$(OS_NCASE) ; \
-	fi
-	if [ -d "../lib" ]; then \
-		svn cleanup ../lib/* ; \
-		svn update ../lib/* ; \
-	fi
-	git pull --rebase
-	git submodule update --init --recursive
-	git submodule foreach git checkout master
-	git submodule foreach git pull --rebase origin master
+	python3 ./build_files/utils/make_update.py
 
 format: .FORCE
 	PATH="../lib/${OS_NCASE}/llvm/bin/:$(PATH)" \