build: Bump devDependencies to latest
build: Bump devDependencies to latest

 grunt-stylelint             0.9.0  →  0.10.0
 stylelint                   8.2.0  →   9.2.0
 stylelint-config-wikimedia  0.4.2  →   0.4.3

Change-Id: Ic9ebf598f2e40d302b5940b6fd4636daa32bc873

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui