Fix an iOS reference in testbed cloning. (#272)

Author: johnzhou721

Makefile

@@ -663,7 +663,7 @@ $$(PYTHON_XCFRAMEWORK-$(os))/Info.plist: \
 
 ifeq ($(filter $(os),iOS visionOS),$(os))
 	@echo ">>> Clone testbed project for $(os)"
-	$(HOST_PYTHON) $$(PYTHON_SRCDIR-$$(firstword $$(SDK_TARGETS-$$(firstword $$(SDKS-$(os))))))/iOS/testbed clone --framework $$(PYTHON_XCFRAMEWORK-$(os)) support/$(PYTHON_VER)/$(os)/testbed
+	$(HOST_PYTHON) $$(PYTHON_SRCDIR-$$(firstword $$(SDK_TARGETS-$$(firstword $$(SDKS-$(os))))))/$(os)/testbed clone --framework $$(PYTHON_XCFRAMEWORK-$(os)) support/$(PYTHON_VER)/$(os)/testbed
 endif
 
 	@echo ">>> Create VERSIONS file for $(os)"