chore: Upgrade stylelint
chore: Upgrade stylelint

For a while, we were forced to use a fork of stylelint with a
bugfix necessary for our test bots to run the tool.
That behavior has now been merged into normal stylelint, so we
can stop using that fork.

Change-Id: I51196f8dab73ac1f814137d2f191a08c231fd369

shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player