build: run embedtest using node executable

We should use the node executable to run this test, instead of
counting on embedtest, the binary being tested, as the test runner.
Otherwise bugs can go unnoticed if the embedtest binary itself
does not work correctly.

Makefile

@@ -286,7 +286,7 @@ coverage-report-js:
 # Runs the C++ tests using the built `cctest` executable.
 cctest: all
 	@out/$(BUILDTYPE)/$@ --gtest_filter=$(GTEST_FILTER)
-	@out/$(BUILDTYPE)/embedtest "require('./test/embedding/test-embedding.js')"
+	$(NODE) ./test/embedding/test-embedding.js
 
 .PHONY: list-gtests
 list-gtests:
@@ -550,7 +550,7 @@ test-ci: | clear-stalled bench-addons-build build-addons build-js-native-api-tes
 	$(PYTHON) tools/test.py $(PARALLEL_ARGS) -p tap --logfile test.tap \
 		--mode=$(BUILDTYPE_LOWER) --flaky-tests=$(FLAKY_TESTS) \
 		$(TEST_CI_ARGS) $(CI_JS_SUITES) $(CI_NATIVE_SUITES) $(CI_DOC)
-	out/Release/embedtest 'require("./test/embedding/test-embedding.js")'
+	$(NODE) ./test/embedding/test-embedding.js
 	$(info Clean up any leftover processes, error if found.)
 	ps awwx | grep Release/node | grep -v grep | cat
 	@PS_OUT=`ps awwx | grep Release/node | grep -v grep | awk '{print $$1}'`; \