Update OOUI to v0.50.4
Release notes: https://gerrit.wikimedia.org/g/oojs/ui/+/v0.50.4/History.md
Bug: T369597 Bug: T369666 Depends-On: I23ed96557e0c1b30528fd7c4d81ade8dfd5be80e Change-Id: I384eeead649dfa81c1dacf2fc461a2be515256d5