Makefile: fix rebuild on install

Makefile.in

@@ -113,6 +113,7 @@ $(OBJDIR)/.build-umu-vendored: | $(OBJDIR)
 	sed -i 's/setuptools>=64,<74/setuptools/' subprojects/pyzstd/pyproject.toml
 	cd subprojects/pyzstd && $(PYTHON_INTERPRETER) -m build -wn -C=--build-option=--dynamic-link-zstd --outdir=$(OBJDIR)
 	cp -a subprojects/pyzstd/$(OBJDIR)/*.whl subprojects/urllib3/$(OBJDIR)/*.whl $(OBJDIR)
+	touch $(@)
 
 .PHONY: umu-vendored
 umu-vendored: $(OBJDIR)/.build-umu-vendored
@@ -186,6 +187,7 @@ PYTHON_PLATFORM_TAG = $(shell $(PYTHON_INTERPRETER) -c 'import sysconfig; print(
 $(OBJDIR)/.build-umu-delta: | $(OBJDIR)
 	$(info :: Building delta dependencies )
 	cargo build -r --target-dir $(OBJDIR)
+	touch $(@)
 
 .PHONY: umu-delta
 umu-delta: $(OBJDIR)/.build-umu-delta