Add only-allow to devDependencies so it does not require network

This makes it possible to continue using `only-allow` while enabling
the package to be used properly on boxes without internet access, e.g.
internal CI boxes.

Author: chriskrycho

package.json

@@ -75,6 +75,7 @@
     "eslint-plugin-n": "^16.0.1",
     "eslint-plugin-unicorn": "^48.0.0",
     "eslint-plugin-vitest": "^0.2.6",
+    "only-allow": "^1.1.1",
     "prettier-plugin-jsdoc": "^1.0.1",
     "release-it": "^16.1.3",
     "typescript": "^5.1.6",