Fix runtime test failures on Windows (AMD64) with NumPy 2.3

- Update alias checks in test_ctype_assumptions.py
- Use np.dtype() comparison instead of 'is' identity check to handle NumPy 2.0+ distinct type classes
- Account for Windows AMD64 where np.long maps to int32 and np.longdouble maps to float64

Author: pareshjoshij

src/numpy-stubs/@test/runtime/test_ctype_assumptions.py

@@ -28,17 +28,19 @@ def test_longlong_64(char: str) -> None:
     [
         ("byte", "int8"),
         ("short", "int16"),
+        ("intc", np.dtype(np.intc).name),
         ("intp", np.dtype(np.intp).name),
+        ("long", np.dtype(np.long).name),
     ],
 )
 def test_alias_integer(name_c: str, name_expect: str) -> None:
     signed_c: type[np.signedinteger] = getattr(np, name_c)
     signed_expect: type[np.signedinteger] = getattr(np, name_expect)
-    assert signed_c is signed_expect
+    assert np.dtype(signed_c) == np.dtype(signed_expect)
 
     unsigned_c: type[np.unsignedinteger] = getattr(np, f"u{name_c}")
     unsigned_expect: type[np.unsignedinteger] = getattr(np, f"u{name_expect}")
-    assert unsigned_c is unsigned_expect
+    assert np.dtype(unsigned_c) == np.dtype(unsigned_expect)
 
 
 @pytest.mark.parametrize(
@@ -47,10 +49,10 @@ def test_alias_integer(name_c: str, name_expect: str) -> None:
         ("half", "float16"),
         ("single", "float32"),
         ("double", "float64"),
-
+        ("longdouble", np.dtype(np.longdouble).name),
     ],
 )
 def test_alias_floating(name_c: str, name_expect: str) -> None:
     floating_c: type[np.floating] = getattr(np, name_c)
     floating_expect: type[np.floating] = getattr(np, name_expect)
-    assert floating_c is floating_expect
+    assert np.dtype(floating_c) == np.dtype(floating_expect)