Fix test_ensure_multivariate_data on 32-bit systems

In that case, the default int is also 32-bit, so the test will fail to
be equal to `int64`.

This is similar to matplotlib#30629.

Author: QuLogic

lib/matplotlib/tests/test_colors.py

@@ -2102,15 +2102,15 @@ def test_ensure_multivariate_data():
     data = [[0, 0, 0], [1, 1, 1]]
     mdata = mcolorizer._ensure_multivariate_data(data, 2)
     assert mdata.shape == (3,)
-    assert mdata.dtype.fields['f0'][0] == np.int64
-    assert mdata.dtype.fields['f1'][0] == np.int64
+    assert np.issubdtype(mdata.dtype.fields['f0'][0], np.integer)
+    assert np.issubdtype(mdata.dtype.fields['f1'][0], np.integer)
 
     # test input of floats, ints as tuple of lists
     data = ([0.0, 0.0], [1, 1])
     mdata = mcolorizer._ensure_multivariate_data(data, 2)
     assert mdata.shape == (2,)
     assert mdata.dtype.fields['f0'][0] == np.float64
-    assert mdata.dtype.fields['f1'][0] == np.int64
+    assert np.issubdtype(mdata.dtype.fields['f1'][0], np.integer)
 
     # test input of array of floats
     data = np.array([[0.0, 0, 0], [1, 1, 1]])