pythongh-145098: Fix incorrect type name in dict_vectorcall error message

dict_vectorcall() is shared by both dict and frozendict. When called
with too many positional arguments, it previously hardcoded "dict" in
the error message even when invoked as frozendict.

For example, `frozendict(1, 2)` raised:
  TypeError: dict expected at most 1 argument, got 2

After this fix it correctly raises:
  TypeError: frozendict expected at most 1 argument, got 2

https://claude.ai/code/session_01EdeU6enhg5YoLvKmBPpiZf

Author: claude

Lib/test/test_dict.py

@@ -1746,6 +1746,10 @@ def test_constructor(self):
         with self.assertRaises(TypeError):
             dict.__init__(d, x=1)
 
+        # Error message uses "frozendict", not "dict"
+        with self.assertRaisesRegex(TypeError, r"frozendict expected at most 1"):
+            frozendict(1, 2)
+
     def test_copy(self):
         d = frozendict(x=1, y=2)
         d2 = d.copy()

Objects/dictobject.c

@@ -5107,7 +5107,7 @@ dict_vectorcall(PyObject *type, PyObject * const*args,
                 size_t nargsf, PyObject *kwnames)
 {
     Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);
-    if (!_PyArg_CheckPositional("dict", nargs, 0, 1)) {
+    if (!_PyArg_CheckPositional(((PyTypeObject*)type)->tp_name, nargs, 0, 1)) {
         return NULL;
     }