FIX: do not mutate `this.attrs` and `this.actions` (#23125)

Prior to this fix we would always re-set `this.attrs` with `this.attrs` when defined, which is both wasteful but also dangerous as `this.attrs` can possibly error when mutated.

app/assets/javascripts/select-kit/addon/components/select-kit.js

@@ -1127,8 +1127,8 @@ export default Component.extend(
     },
 
     _deprecateMutations() {
-      this.actions = this.actions || {};
-      this.attrs = this.attrs || {};
+      this.actions ??= {};
+      this.attrs ??= {};
 
       if (!this.attrs.onChange && !this.actions.onChange) {
         this._deprecated(