Deprecate isImageType

[radarhere]

Removes isImageType(), which relies on hasattr(t, "im"),

Pillow/src/PIL/Image.py

Lines 125 to 136 in be01d53

	def isImageType(t: Any) -> TypeGuard[Image]:
	"""
	Checks if an object is an image object.
	.. warning::
	This function is for internal use only.
	:param t: object to check if it's an image
	:returns: True if the object is an image
	"""
	return hasattr(t, "im")

and instead uses isinstance(im, Image).

I've also made a similar change in ImageMath, replacing hasattr(v, "im") with isinstance(v, Image.Image).

[Yay295]

This elif could be removed now since it does the same thing as the else below it.

[radarhere]

You're right, I've updated the commit.

[hugovk]

Thank you.