Size Autocomplete relative to the RoomView height rather than the viewport height

res/css/structures/_RoomView.pcss

@@ -76,6 +76,8 @@ Please see LICENSE files in the repository root for full details.
     flex-direction: column;
     flex: 1;
     min-width: 0;
+    container-type: size;
+    container-name: roomview;
 
     .mx_RoomView_messagePanel,
     .mx_RoomView_messagePanelSpinner,

res/css/views/rooms/_Autocomplete.pcss

@@ -65,7 +65,12 @@
     margin: 12px;
     height: 100%;
     overflow-y: scroll;
-    max-height: 35vh;
+}
+
+@container roomview (height >= 0px) {
+    .mx_Autocomplete_Completion_container_pill {
+        max-height: 40cqh;
+    }
 }
 
 .mx_Autocomplete_Completion_container_truncate {