Fix type annotations in pandas.core.computation
Part of  #25882

The files in pandas.core.computation have the following errors:
```
pandas/core/computation/ops.py:169: error: Read-only property cannot override read-write property
pandas/core/computation/pytables.py:59: error: Read-only property cannot override read-write property
pandas/core/computation/pytables.py:384: error: Incompatible types in assignment (expression has type "Type[pandas.core.computation.pytables.Constant]", base class "BaseExprVisitor" defined the type as "Type[pandas.core.computation.ops.Constant]")
```

Pull request to follow.