Internal - Room Search Fix (#721)

<!-- Please read
https://github.com/SableClient/Sable/blob/dev/CONTRIBUTING.md before
submitting your pull request -->

### Description
Fixes the rerender cycle by making it sure it redoes the math if the
state changes instead

It doesn't have or need a changelog as it is a bug encountered only in
the dev branch

Fixes #

#### Type of change

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

### Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings

### AI disclosure:

- [ ] Partially AI assisted (clarify which code was AI assisted and
briefly explain what it does).
- [ ] Fully AI generated (explain what all the generated code does in
moderate detail).
<!-- Write any explanation required here, but do not generate the
explanation using AI!! You must prove you understand what the code in
this PR does. -->
The callas disregard for the state of the room compelled and educated in
writing the pr 😔😔😔

Author: 7w1

src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx

@@ -1,5 +1,5 @@
 import type { KeyboardEvent as ReactKeyboardEvent } from 'react';
-import { useCallback, useEffect } from 'react';
+import { useCallback, useEffect, useMemo } from 'react';
 import type { Editor } from 'slate';
 import { ReactEditor } from 'slate-react';
 import { Avatar, Icon, Icons, MenuItem, Text } from 'folds';
@@ -83,7 +83,11 @@ export function RoomMentionAutocomplete({
   const mx = useMatrixClient();
   const mDirects = useAtomValue(mDirectAtom);
 
-  const allRooms = useAtomValue(allRoomsAtom).toSorted(factoryRoomIdByActivity(mx));
+  const allRoomsFromAtom = useAtomValue(allRoomsAtom);
+  const allRooms = useMemo(
+    () => allRoomsFromAtom.toSorted(factoryRoomIdByActivity(mx)),
+    [allRoomsFromAtom, mx]
+  );
 
   const [result, search, resetSearch] = useAsyncSearch(
     allRooms,