UX: omit date in user stream for small action posts (#31236)

This change makes it possible to render the action code from small
action posts (ie. close topic etc) without the relative date. This is
applied in the user stream items to prevent duplication of dates.

app/assets/javascripts/discourse/app/components/post-action-description.gjs

@@ -3,7 +3,7 @@ import { actionDescriptionHtml } from "discourse/widgets/post-small-action";
 
 export default class PostActionDescription extends Component {
   get description() {
-    if (this.args.actionCode && this.args.createdAt) {
+    if (this.args.actionCode) {
       return actionDescriptionHtml(
         this.args.actionCode,
         this.args.createdAt,

app/assets/javascripts/discourse/app/components/user-stream.gjs

@@ -186,7 +186,6 @@ export default class UserStreamComponent extends Component {
       <:abovePostItemExcerpt as |post|>
         <PostActionDescription
           @actionCode={{post.action_code}}
-          @createdAt={{post.created_at}}
           @username={{post.action_code_who}}
           @path={{post.action_code_path}}
         />

app/assets/javascripts/discourse/app/widgets/post-small-action.js

@@ -12,10 +12,11 @@ import { createWidget } from "discourse/widgets/widget";
 import { i18n } from "discourse-i18n";
 
 export function actionDescriptionHtml(actionCode, createdAt, username, path) {
-  const dt = new Date(createdAt);
-  const when = autoUpdatingRelativeAge(dt, {
-    format: "medium-with-ago-and-on",
-  });
+  const when = createdAt
+    ? autoUpdatingRelativeAge(new Date(createdAt), {
+        format: "medium-with-ago-and-on",
+      })
+    : "";
 
   let who = "";
   if (username) {