Fix an issue with creating a series from scalar when dtype='category'

[galipremsagar]

Description

When dtype='category' we seem to error:

File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/cuml/preprocessing/LabelEncoder.py", line 218, in transform
2024-04-05T19:37:35.8255262Z E                 y = cudf.Series('a', dtype="category")
2024-04-05T19:37:35.8257445Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8260865Z E               File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/nvtx/nvtx.py", line 116, in inner
2024-04-05T19:37:35.8264174Z E                 result = func(*args, **kwargs)
2024-04-05T19:37:35.8266324Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8270003Z E               File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/cudf/core/series.py", line 648, in __init__
2024-04-05T19:37:35.8273382Z E                 column = as_column(
2024-04-05T19:37:35.8275420Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8279989Z E               File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/cudf/core/column/column.py", line 2022, in as_column
2024-04-05T19:37:35.8281584Z E                 arbitrary = cudf.Scalar(arbitrary, dtype=dtype)
2024-04-05T19:37:35.8282461Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8283768Z E               File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/cudf/core/scalar.py", line 57, in __call__
2024-04-05T19:37:35.8285137Z E                 obj = super().__call__(value, dtype=dtype)
2024-04-05T19:37:35.8285959Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8287757Z E               File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/cudf/core/scalar.py", line 128, in __init__
2024-04-05T19:37:35.8289232Z E                 self._host_value, self._host_dtype = self._preprocess_host_value(
2024-04-05T19:37:35.8290183Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8291705Z E               File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/cudf/core/scalar.py", line 222, in _preprocess_host_value
2024-04-05T19:37:35.8293212Z E                 value = to_cudf_compatible_scalar(value, dtype=dtype)
2024-04-05T19:37:35.8294438Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8296026Z E               File "/pyenv/versions/3.11.9/lib/python3.11/site-packages/cudf/utils/dtypes.py", line 257, in to_cudf_compatible_scalar
2024-04-05T19:37:35.8297604Z E                 if isinstance(val, str) and np.dtype(dtype).kind == "M":
2024-04-05T19:37:35.8298543Z E                 ^^^^^^^^^^^^^^^^^
2024-04-05T19:37:35.8308752Z E             TypeError: data type 'category' not understood

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

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[AyodeAwe]

Merging on request