FIX: relies on native focus behavior in chat emoji picker (#21092)

This codepath was responsible to scroll to the first emoji of a section, however `scrollIntoView` was not super reliable and was also causing the whole page to scroll with drawer. This is also simply not necessary code as native focus behavior will scroll to the element.

plugins/chat/assets/javascripts/discourse/components/chat-emoji-picker.hbs

@@ -197,7 +197,6 @@
                       this.chatEmojiReactionStore.diversity
                     }}
                     loading="lazy"
-                    {{on "focus" this.didFocusFirstEmoji}}
                   />
                 {{/let}}
 

plugins/chat/assets/javascripts/discourse/components/chat-emoji-picker.js

@@ -357,14 +357,6 @@ export default class ChatEmojiPicker extends Component {
     }
   }
 
-  @action
-  didFocusFirstEmoji(event) {
-    event.preventDefault();
-    const section = event.target.closest(".chat-emoji-picker__section").dataset
-      .section;
-    this.didRequestSection(section);
-  }
-
   @action
   didRequestSection(section) {
     const scrollableContent = document.querySelector(
@@ -388,12 +380,10 @@ export default class ChatEmojiPicker extends Component {
 
     schedule("afterRender", () => {
       document
-        .querySelector(`.chat-emoji-picker__section[data-section="${section}"]`)
-        .scrollIntoView({
-          behavior: "auto",
-          block: "start",
-          inline: "start",
-        });
+        .querySelector(
+          `.chat-emoji-picker__section[data-section="${section}"] .emoji:nth-child(1)`
+        )
+        .focus();
 
       later(() => {
         // iOS hack to avoid blank div when requesting section during momentum

plugins/chat/test/javascripts/components/chat-emoji-picker-test.js

@@ -128,7 +128,8 @@ module("Discourse Chat | Component | chat-emoji-picker", function (hooks) {
     await click(`.chat-emoji-picker__section-btn[data-section="objects"]`);
 
     assert.true(
-      document.querySelector("#ember-testing-container").scrollTop > 0,
+      document.querySelector(".chat-emoji-picker__scrollable-content")
+        .scrollTop > 0,
       "it scrolls to the section"
     );
   });