[FIX] Sidebar Room list extended preview not updating on new messages.

[gabriellsh]

Proposed changes (including videos or screenshots)

Issue(s)

Steps to test or reproduce

In the sidebar, choose extended mode.
I'll use the channel GENERAL as the example.

With user one, join GENERAL.
With another user, join GENERAL.
On the first user, click the homepage button, or open another room, so that the room GENERAL is NOT open.

With user 2, send a message to channel GENERAL.
Now, send a different message.

On user 1, in the sidebar, the preview message should be the last sent message, which is not the case.

Further comments

[codecov]

Codecov Report

Merging #27259 (1e4bfef) into develop (1c5f950) will increase coverage by 0.24%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop   #27259      +/-   ##
===========================================
+ Coverage    40.89%   41.14%   +0.24%     
===========================================
  Files          854      819      -35     
  Lines        18751    17929     -822     
  Branches      2053     1986      -67     
===========================================
- Hits          7669     7377     -292     
+ Misses       10791    10267     -524     
+ Partials       291      285       -6     

Flag	Coverage Δ
e2e	41.14% <100.00%> (+0.24%)	⬆️

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