fix(helpers): handle any type in RequiredKeysOf

When RequiredKeysOfHelper<T> evaluates to 'any' (e.g., when T is 'any'),
RequiredKeysOf should return 'never' to indicate no required keys.

This fixes the issue where using createClient<any>() with placeholder
OpenAPI types would incorrectly require the second parameter in API calls
like client.GET('/path').

The fix adds an additional conditional check:
RequiredKeysOfHelper<T> extends any ? never

This ensures that when paths type is 'any' (common when using placeholder
types or fallback schemas), the second parameter becomes optional, allowing
builds to succeed without type errors.

Author: jtomaszewski

packages/openapi-typescript-helpers/src/index.ts

@@ -198,4 +198,4 @@ type RequiredKeysOfHelper<T> = {
   [K in keyof T]: {} extends Pick<T, K> ? never : K;
 }[keyof T];
 /** Get the required keys of an object, or `never` if no keys are required */
-export type RequiredKeysOf<T> = RequiredKeysOfHelper<T> extends undefined ? never : RequiredKeysOfHelper<T>;
+export type RequiredKeysOf<T> = RequiredKeysOfHelper<T> extends undefined ? never : RequiredKeysOfHelper<T> extends any ? never : RequiredKeysOfHelper<T>;