tools: add missing package-lock to clang-format

`npm ci` fails where there is no package-lock.json.
Also add the `node_modules` directory to .gitignore.

PR-URL: #22500
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

.gitignore

@@ -110,6 +110,9 @@ deps/npm/node_modules/.bin/
 # api docs artifacts
 tools/doc/node_modules
 
+# clang-format artifacts
+tools/clang-format/node_modules
+
 # test artifacts
 tools/remark-cli/node_modules
 tools/remark-preset-lint-node/node_modules