fix: use ReadonlyArray generic instead of readonly array syntax

- Change readonly unknown[] to ReadonlyArray<unknown>
- Complies with project's ESLint config that disallows inline readonly syntax

Author: VedantMadane

packages/vue-query/src/__tests__/queryOptions.test-d.ts

@@ -18,7 +18,7 @@ describe('queryOptions', () => {
       (() => Promise<number>) | undefined
     >()
     expectTypeOf(options.staleTime).toMatchTypeOf<number | undefined>()
-    expectTypeOf(options.queryKey).toMatchTypeOf<readonly unknown[]>()
+    expectTypeOf(options.queryKey).toMatchTypeOf<ReadonlyArray<unknown>>()
   })
 
   it('should not allow excess properties', () => {