Use phpcs to forbid short array syntax

This bumps mediawiki/mediawiki-codesniffer to the earliest version that
included the upstream sniff that forbade short array syntax. All failing
rules were disabled so it can be made voting immediately, but some of
these should probably be fixed (e.g. no closing PHP tags), and can
probably be auto-fixed rather easily.

Should hopefully prevent T143635 in the future, as long as phpcs is run
before tarballs are published (and not after by CI).

Change-Id: If336a4091c11228d2a2f78de11b69450f5c93874