setup's `license` parameter should be a short string

[sschuberth]

Currently, setup's license is set to the full text of the MIT license as read from the LICENSE file:

python-pptx/setup.py

Line 26 in 71d1ca0

license = ascii_bytes_from(thisdir, "LICENSE")

python-pptx/setup.py

Line 41 in 71d1ca0

LICENSE = license

python-pptx/setup.py

Line 77 in b31cf20

"license": LICENSE,

This is wrong as "license" should be a short string and should just contain the name of the license (ideally as an SPDX ID; so here just "MIT"), not its text.

[scanny]

Sounds good to me. I'll fix that up next time I'm in there :)

[scanny]

Fixed in version 0.6.22 circa Aug 20, 2023.