DEV: Fix flaky emoji-store tests

This set of tests cleared the emoji store *before* each test, while the other set - *after*. So if these were run first, they would break a single test from the other set.

test/javascripts/acceptance/emoji-picker-test.js

@@ -3,7 +3,7 @@ import { IMAGE_VERSION as v } from "pretty-text/emoji/version";
 
 acceptance("EmojiPicker", {
   loggedIn: true,
-  beforeEach() {
+  afterEach() {
     const store = Discourse.__container__.lookup("service:emoji-store");
     store.reset();
   }