fix(runtime-dom): ensure readonly type prop on textarea is handled patched as attribute (#2888)

close #2766

Co-authored-by: Thorsten Luenborg <t.luneborg@googlemail.com>

packages/runtime-dom/src/patchProp.ts

@@ -115,5 +115,10 @@ function shouldSetAsProp(
     return false
   }
 
+  // DOMprop "type" is readonly on textarea elements: https://github.com/vuejs/vue-next/issues/2766
+  if (key === 'type' && el.tagName === 'TEXTAREA') {
+    return false
+  }
+
   return key in el
 }