TYP: Non-overlapping identity checks with pd.NaT
Either wrong type annotations in pandas/core/ops/mask_ops.py or there are a few branches that will never get hit (`bool | np.ndarray` can never be `NAType`).

Found in #43744
> pandas/core/ops/mask_ops.py:49: error: Non-overlapping identity check (left operand type: "Union[bool, ndarray[Any, Any]]", right operand type: "NAType")  [comparison-overlap]
> pandas/core/ops/mask_ops.py:66: error: Non-overlapping identity check (left operand type: "Union[bool, ndarray[Any, Any]]", right operand type: "NAType")  [comparison-overlap]
> pandas/core/ops/mask_ops.py:106: error: Non-overlapping identity check (left operand type: "Union[bool, ndarray[Any, Any]]", right operand type: "NAType")  [comparison-overlap]
> pandas/core/ops/mask_ops.py:114: error: Non-overlapping identity check (left operand type: "Union[bool, ndarray[Any, Any]]", right operand type: "NAType")  [comparison-overlap]

edit: happens in a few more places as well

> pandas/core/arrays/timedeltas.py:537: error: Non-overlapping identity check (left operand type: "Timedelta", right operand type: "NaTType")  [comparison-overlap]
> pandas/core/arrays/timedeltas.py:594: error: Non-overlapping identity check (left operand type: "Timedelta", right operand type: "NaTType")  [comparison-overlap]
> pandas/core/arrays/timedeltas.py:637: error: Non-overlapping identity check (left operand type: "Timedelta", right operand type: "NaTType")  [comparison-overlap]
> pandas/core/arrays/timedeltas.py:705: error: Non-overlapping identity check (left operand type: "Timedelta", right operand type: "NaTType")  [comparison-overlap]
> 
> pandas/core/arrays/masked.py:341: error: Non-overlapping identity check (left operand type: "Union[Union[str, int, float, bool], Union[Period, Timestamp, Timedelta, Interval]]", right operand type: "NoDefault")  [comparison-overlap]
> pandas/core/arrays/masked.py:349: error: Non-overlapping identity check (left operand type: "Union[Union[str, int, float, bool], Union[Period, Timestamp, Timedelta, Interval]]", right operand type: "NAType")  [comparison-overlap]