Use _ensure_mutable()

[radarhere]

Pillow/src/PIL/Image.py

Lines 2073 to 2075 in b7e0570

	if self.readonly:
	self._copy()
	self.load()

and

Pillow/src/PIL/ImageDraw.py

Lines 79 to 81 in b7e0570

	im.load()
	if im.readonly:
	im._copy() # make it writeable

are virtually identical to

Pillow/src/PIL/Image.py

Lines 629 to 633 in b7e0570

	def _ensure_mutable(self) -> None:
	if self.readonly:
	self._copy()
	else:
	self.load()

So they can be replaced with calls to _ensure_mutable()