build: Re-crush SVGs after #281
Sketch has the bad attitude to put advertisment into SVG's desc tag.
We got rid of it in https://github.com/wikimedia/WikimediaUI-Style-Guide/commit/4def9c4f40b1b131b1c2b1fcdad780421bccde99#diff-35b4a816e0441e6a375cd925af50752cR309
with only circumventing the issue for the time being. Re-crushing the
SVGs in this step.