Disallow `it.only` via ESLint

.eslintrc.json

{
  "rules": {
    "no-restricted-syntax": [
      "error",
      {
        "selector": "CallExpression[callee.object.type='Identifier'][callee.object.name='it'][callee.property.type='Identifier'][callee.property.name='only']",
        "message": "it.only is only allowed during development"
      }
    ]
  }
}