Use _ensure_mutable

Author: radarhere

src/PIL/ImageDraw.py

@@ -76,9 +76,7 @@ def __init__(self, im: Image.Image, mode: str | None = None) -> None:
            must be the same as the image mode.  If omitted, the mode
            defaults to the mode of the image.
         """
-        im.load()
-        if im.readonly:
-            im._copy()  # make it writeable
+        im._ensure_mutable()
         blend = 0
         if mode is None:
             mode = im.mode