build: do not lint fixtures in make lint-md

PR-URL: #22549
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>

Makefile

@@ -1087,7 +1087,8 @@ tools/.docmdlintstamp: $(LINT_MD_DOC_FILES)
 LINT_MD_TARGETS = src lib benchmark test tools/doc tools/icu
 LINT_MD_ROOT_DOCS := $(wildcard *.md)
 LINT_MD_MISC_FILES := $(shell find $(LINT_MD_TARGETS) -type f \
-  -not -path '*node_modules*' -name '*.md') $(LINT_MD_ROOT_DOCS)
+  -not -path '*node_modules*' -not -path 'test/fixtures/*' -name '*.md') \
+  $(LINT_MD_ROOT_DOCS)
 run-lint-misc-md = tools/lint-md.js -q -f $(LINT_MD_MISC_FILES)
 # Lint other changed markdown files maintained by us
 tools/.miscmdlintstamp: $(LINT_MD_MISC_FILES)