Fixes TS issue with mismatched type for deprecate

addon/ember-test-waiters/index.ts

@@ -7,7 +7,9 @@ deprecate(
     id: 'ember-test-waiters-legacy-module-name',
     until: '3.0.0',
     for: 'ember-test-waiters',
-    since: '2.2.0',
+    since: {
+      enabled: '2.2.0',
+    },
   }
 );
 

types/custom-ember-debug.d.ts

@@ -0,0 +1,35 @@
+import '@ember/debug';
+
+export type DeprecationStages = 'available' | 'enabled';
+
+declare module '@ember/debug' {
+  export function deprecate(
+    message: string,
+    test: boolean,
+    options: {
+      /**
+       * A unique id for this deprecation. The id can be used by Ember debugging
+       * tools to change the behavior (raise, log or silence) for that specific
+       * deprecation. The id should be namespaced by dots, e.g.
+       * `"view.helper.select"`.
+       */
+      id: string;
+      /**
+       * The version of Ember when this deprecation warning will be removed.
+       */
+      until: string;
+      /**
+       * A namespace for the deprecation, usually the package name
+       */
+      for: string;
+      /**
+       * Describes when the deprecation became available and enabled
+       */
+      since: Partial<Record<DeprecationStages, string>>;
+      /**
+       * An optional url to the transition guide on the emberjs.com website.
+       */
+      url?: string | undefined;
+    }
+  ): void;
+}