Ignore putpalette rawmode if data is an ImagePalette

[radarhere]

If an ImagePalette is passed to putpalette(),

Pillow/src/PIL/Image.py

Lines 2135 to 2138 in 7d67d37

	def putpalette(
	self,
	data: ImagePalette.ImagePalette | bytes | Sequence[int],
	rawmode: str = "RGB",

then the rawmode from the palette is used.

Pillow/src/PIL/Image.py

Lines 2163 to 2164 in 7d67d37

	if isinstance(data, ImagePalette.ImagePalette):
	palette = ImagePalette.raw(data.rawmode or "RGB", data.palette)

But only at first? Later, the rawmode argument is used.

Pillow/src/PIL/Image.py

Lines 2169 to 2172 in 7d67d37

	if rawmode.startswith("CMYK"):
	self.palette.mode = "CMYK"
	elif "A" in rawmode:
	self.palette.mode = "RGBA"

If an ImagePalette is passed to putpalette(), let's be simple and consistent and ignore rawmode.

When considering this, you might wonder if the documentation lays out a different expectation. The answer is no - it doesn't even mention that you can pass an ImagePalette in. See https://pillow.readthedocs.io/en/latest/reference/Image.html#PIL.Image.Image.putpalette