tools,build: allow build without remark-cli

[refack]

Refs: #16635 (comment)
The lint target in the Makefile is dependant on remark-cli being installed in /tools/ or alternatively on internet access to the npm registry. The source tarball does not include remark-cli nor ESLint, so this PR uses the same conditional pattern as for lint-js:

node/Makefile

Lines 1082 to 1107 in d597317

	ifneq ("","$(wildcard tools/eslint/)")
	lint:
	@EXIT_STATUS=0 ; \
	$(MAKE) lint-js || EXIT_STATUS=$$? ; \
	$(MAKE) lint-cpp || EXIT_STATUS=$$? ; \
	$(MAKE) lint-md || EXIT_STATUS=$$? ; \
	$(MAKE) lint-addon-docs || EXIT_STATUS=$$? ; \
	exit $$EXIT_STATUS
	CONFLICT_RE=^>>>>>>> [0-9A-Fa-f]+|^<<<<<<< [A-Za-z]+
	lint-ci: lint-js-ci lint-cpp lint-md lint-addon-docs
	@if ! ( grep -IEqrs "$(CONFLICT_RE)" benchmark deps doc lib src test tools ) \
	&& ! ( find . -maxdepth 1 -type f | xargs grep -IEqs "$(CONFLICT_RE)" ); then \
	exit 0 ; \
	else \
	echo "" >&2 ; \
	echo "Conflict marker detected in one or more files. Please fix them first." >&2 ; \
	exit 1 ; \
	fi
	else
	lint:
	@echo "Linting is not available through the source tarball."
	@echo "Use the git repo instead:" \
	"$ git clone https://github.com/nodejs/node.git"
	lint-ci: lint
	endif

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

build,tools

[refack]

CI: https://ci.nodejs.org/job/node-test-pull-request/11317/

[MylesBorins]

This should be included in a general backport of remark for v6.x