Merge pull request #5930 from hugovk/rm-__eq__-readonly

Remove readonly from Image.__eq__

src/PIL/Image.py

@@ -627,7 +627,6 @@ def __eq__(self, other):
             and self.size == other.size
             and self.info == other.info
             and self._category == other._category
-            and self.readonly == other.readonly
             and self.getpalette() == other.getpalette()
             and self.tobytes() == other.tobytes()
         )