Deprecate putpixel value lists

[radarhere]

Resolves #9584

putpixel() says that value accepts a list.

Pillow/src/PIL/Image.py

Lines 2176 to 2178 in 4e0aeba

	def putpixel(
	self, xy: tuple[int, int], value: float | tuple[int, ...] | list[int]
	) -> None:

However, while this works for palette-based values, the issue has pointed out that it doesn't otherwise. When it calls _getink, _getink raises errors that

Pillow/src/_imaging.c

Line 599 in 4e0aeba

PyErr_SetString(PyExc_TypeError, "color must be int or tuple");

We could change _getink to accept lists, but updating this common error message would mean that paste(), new() and ImageDraw inks should all then accept lists. It would seem simpler to accept that this is an outlier, and to prevent putpixel from accepting lists as a value.

Because this is working for palette-based colors, I suggest deprecating that functionality first.