reflect the specified regex correctly in error (#5338)

Author: Tietew

packages/zod/src/v4/core/schemas.ts

@@ -489,7 +489,7 @@ export const $ZodURL: core.$constructor<$ZodURL> = /*@__PURE__*/ core.$construct
             code: "invalid_format",
             format: "url",
             note: "Invalid hostname",
-            pattern: regexes.hostname.source,
+            pattern: def.hostname.source,
             input: payload.value,
             inst,
             continue: !def.abort,