tools: exclude gyp from markdown link checker

The changelog format used in gyp-next does not comply to the rules.

PR-URL: nodejs#35423
Reviewed-By: Ujjwal Sharma <ryzokuken@disroot.org>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

tools/doc/checkLinks.js

@@ -31,6 +31,7 @@ function findMarkdownFilesRecursively(dirPath) {
       entry.name !== 'changelogs' &&
       entry.name !== 'deps' &&
       entry.name !== 'fixtures' &&
+      entry.name !== 'gyp' &&
       entry.name !== 'node_modules' &&
       entry.name !== 'out' &&
       entry.name !== 'tmp'