build: Updating browserslist to 4.16.6
build: Updating browserslist to 4.16.6

* https://npmjs.com/advisories/1747 (CVE-2021-23364)

Change-Id: I218ad34043b94d8093af179788fc73b6c5bb89c2

wikimedia/mediawiki-extensions-RegexFun,wikimedia/mediawiki-extensions-RegexFun