fix(vue3): typo warning -> warn

Signed-off-by: Grigorii K. Shartsev <me@shgk.me>

parts/vue3.js

@@ -34,6 +34,6 @@ module.exports = {
  // Prevent conflicts with native HTML elements
  'vue/multi-word-component-names': 'error',
  // custom event naming convention
- 'vue/custom-event-name-casing': 'warning',
+ 'vue/custom-event-name-casing': 'warn',
  },
 }