Add support for PandasArray for pandas<2.1.0 (#15786)

Only `pandas-2.1.0+` has support for `NumpyExtensionArray` and any version below that only have support for `PandasArray`. This PR make `cudf.pandas` back-ward compatible in that aspect.

Authors:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

Approvers:
  - https://github.com/brandon-b-miller
  - Matthew Roeschke (https://github.com/mroeschke)

URL: #15786

python/cudf/cudf/pandas/_wrappers/pandas.py

@@ -386,17 +386,35 @@ def Index__new__(cls, *args, **kwargs):
     },
 )
 
-NumpyExtensionArray = make_final_proxy_type(
-    "NumpyExtensionArray",
-    _Unusable,
-    pd.arrays.NumpyExtensionArray,
-    fast_to_slow=_Unusable(),
-    slow_to_fast=_Unusable(),
-    additional_attributes={
-        "_ndarray": _FastSlowAttribute("_ndarray"),
-        "_dtype": _FastSlowAttribute("_dtype"),
-    },
-)
+try:
+    from pandas.arrays import NumpyExtensionArray as pd_NumpyExtensionArray
+
+    NumpyExtensionArray = make_final_proxy_type(
+        "NumpyExtensionArray",
+        _Unusable,
+        pd_NumpyExtensionArray,
+        fast_to_slow=_Unusable(),
+        slow_to_fast=_Unusable(),
+        additional_attributes={
+            "_ndarray": _FastSlowAttribute("_ndarray"),
+            "_dtype": _FastSlowAttribute("_dtype"),
+        },
+    )
+
+except ImportError:
+    from pandas.arrays import PandasArray as pd_PandasArray
+
+    PandasArray = make_final_proxy_type(
+        "PandasArray",
+        _Unusable,
+        pd_PandasArray,
+        fast_to_slow=_Unusable(),
+        slow_to_fast=_Unusable(),
+        additional_attributes={
+            "_ndarray": _FastSlowAttribute("_ndarray"),
+            "_dtype": _FastSlowAttribute("_dtype"),
+        },
+    )
 
 TimedeltaArray = make_final_proxy_type(
     "TimedeltaArray",

python/cudf/cudf_pandas_tests/test_cudf_pandas.py

@@ -1241,8 +1241,12 @@ def test_pickle_groupby(dataframe):
 
 def test_numpy_extension_array():
     np_array = np.array([0, 1, 2, 3])
-    xarray = xpd.arrays.NumpyExtensionArray(np_array)
-    array = pd.arrays.NumpyExtensionArray(np_array)
+    try:
+        xarray = xpd.arrays.NumpyExtensionArray(np_array)
+        array = pd.arrays.NumpyExtensionArray(np_array)
+    except AttributeError:
+        xarray = xpd.arrays.PandasArray(np_array)
+        array = pd.arrays.PandasArray(np_array)
 
     tm.assert_equal(xarray, array)