See https://docs.npmjs.com/cli/ci.html

--- a/Makefile
+++ b/Makefile
@@ -84,7 +84,7 @@
 	cp util/root-certs.json lib/internal
 	touch lib/BUILT
 node_modules/BUILT: package.json
-	npm install
+	npm ci
 	touch node_modules/BUILT
 
 deps/duktape/src-low/duktape.c: $(shell find deps/duktape/src-input)