## `FrozenDateTimeFactory.tick`
The `delta` argument is capable of handling `float`s. In previous versions of
freezgun, the `.pyi` type annotations were correctly reflecting that. For some
reason, when moving the type annotations into the `.py` file, this information
got lost.

Further, checking for `isinstance(delta, numbers.Real)` is probably not what
was intended as `fraction.Fraction` is a subclass of `Real`, but will cause an
error when passed into `datetime.timedelta(seconds=delta)`.

## `StepTickTimeFactory.tick`
The same issue with the type hint applies here.

Fruther, passing an integer/float `delta` would lead to that number being added
to the frozen `datetime.datetime`, which is not a valid operation
(`TypeError: unsupported operand type(s) for +: 'datetime.datetime' and 'int'`).