fix(types): accept number type as key on Vue.set/delete (#8707) (#8709)

Author: nel215

types/test/vue-test.ts

@@ -87,8 +87,10 @@ class Test extends Vue {
     this.nextTick(() => {});
     this.nextTick().then(() => {});
     this.set({}, "", "");
+    this.set({}, 1, "");
     this.set([true, false, true], 1, true);
     this.delete({}, "");
+    this.delete({}, 1);
     this.delete([true, false], 0);
     this.directive("", {bind() {}});
     this.filter("", (value: number) => value);

types/vue.d.ts

@@ -91,9 +91,9 @@ export interface VueConstructor<V extends Vue = Vue> {
 
   nextTick(callback: () => void, context?: any[]): void;
   nextTick(): Promise<void>
-  set<T>(object: object, key: string, value: T): T;
+  set<T>(object: object, key: string | number, value: T): T;
   set<T>(array: T[], key: number, value: T): T;
-  delete(object: object, key: string): void;
+  delete(object: object, key: string | number): void;
   delete<T>(array: T[], key: number): void;
 
   directive(