bpo-42065: Fix incorrectly formatted _codecs.charmap_decode error message (GH-19940)

(cherry picked from commit 3635388f52b42e5280229104747962117104c453)

Co-authored-by: Max Bernstein <tekknolagi@users.noreply.github.com>
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 3c2383d..d5fbf15 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -8160,7 +8160,7 @@
                 goto Undefined;
             if (value < 0 || value > MAX_UNICODE) {
                 PyErr_Format(PyExc_TypeError,
-                             "character mapping must be in range(0x%lx)",
+                             "character mapping must be in range(0x%x)",
                              (unsigned long)MAX_UNICODE + 1);
                 goto onError;
             }