tools: remove dangling eslint symlink

The tools/eslint/node_modules/.bin/eslint symlink was unused by node,
but was present, and pointed at a non-existent file. This causes
problems for tooling.

Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
PR-URL: #9299