tools: delete redundant .eslintignore rule

The `node_modules` rule below is treated as a glob pattern,
so it includes the `tools/node_modules` folder.

PR-URL: https://github.com/nodejs/node/pull/20203
Refs: https://eslint.org/docs/user-guide/configuring#ignoring-files-and-directories
Refs: https://git-scm.com/docs/gitignore#_pattern_format
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>

.eslintignore

@@ -5,7 +5,6 @@ test/addons/??_*
 test/es-module/test-esm-dynamic-import.js
 test/fixtures
 test/message/esm_display_syntax_error.mjs
-tools/node_modules
 tools/icu
 tools/remark-*
 node_modules