Update dtypes.py

removed if statements

Author: road-1

pandas/core/dtypes/dtypes.py

@@ -2277,18 +2277,6 @@ def name(self) -> str:  # type: ignore[override]
     @cache_readonly
     def numpy_dtype(self) -> np.dtype:
         """Return an instance of the related numpy dtype"""
-        if pa.types.is_timestamp(self.pyarrow_dtype):
-            # pa.timestamp(unit).to_pandas_dtype() returns ns units
-            # regardless of the pyarrow timestamp units.
-            # This can be removed if/when pyarrow addresses it:
-            # https://github.com/apache/arrow/issues/34462
-            return np.dtype(f"datetime64[{self.pyarrow_dtype.unit}]")
-        if pa.types.is_duration(self.pyarrow_dtype):
-            # pa.duration(unit).to_pandas_dtype() returns ns units
-            # regardless of the pyarrow duration units
-            # This can be removed if/when pyarrow addresses it:
-            # https://github.com/apache/arrow/issues/34462
-            return np.dtype(f"timedelta64[{self.pyarrow_dtype.unit}]")
         if pa.types.is_string(self.pyarrow_dtype) or pa.types.is_large_string(
             self.pyarrow_dtype
         ):