chore: enabled syntax highlighting

[0xflotus]

I enabled the syntax highlighting feature in the image-file-formats.rst

[hugovk]

Thanks for the PR, however the default for literal blocks (::) is already Python and we've not changed it using highlight_language.

• https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#showing-code-examples
• https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html#rst-literal-blocks
• https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#directive-code-block

So this PR doesn't change anything other than making it more explicit, which I don't think we need in this particular case.

[0xflotus]

Ok, but there is already a use of it in the lines 1402 and 1413:

Pillow/docs/handbook/image-file-formats.rst

Lines 1402 to 1417 in 7303825

	.. code-block:: python
	from PIL import Image
	with Image.open("drawing.wmf") as im:
	im.load(dpi=144)
	To add other read or write support, use
	:py:func:`PIL.WmfImagePlugin.register_handler` to register a WMF and EMF
	handler.
	.. code-block:: python
	from PIL import Image
	from PIL import WmfImagePlugin

So I thought it would be consistent.

[radarhere]

I've created PR #6958 as a possible alternative to this.

[radarhere]

#6958 has been merged instead.