[mmporong]

Changes proposed in this pull request:

• In the ImageStat.Stat docstring, rename :param image: to :param image_or_list:, the name __init__() takes.
• In the Image.eval() docstring, rename :param function: to :param \*args:, since the function is passed positionally through *args. The docstring becomes a raw string for the backslash, as in ImageShow.show().

The rendered docs show a signature and a parameter list that disagree, for example __init__(image_or_list, mask=None) with a parameter called image. Passing the documented names as keywords fails:

>>> ImageStat.Stat(image=im)
TypeError: Stat.__init__() got an unexpected keyword argument 'image'
>>> Image.eval(im, function=lambda v: v * 2)
TypeError: eval() got an unexpected keyword argument 'function'

I found these two by comparing every :param name: in src/PIL/*.py with the parameters of its function; no other mismatches turned up. An autodoc build of the two objects with --fail-on-warning passes and lists image_or_list and *args, and ruff, black and the other pre-commit hooks pass on the changed files.