Makes the avatar of the user menu non-draggable (matrix-org#8765)

Author: luixxiul

res/css/structures/_UserMenu.scss

@@ -22,10 +22,14 @@ limitations under the License.
     .mx_AccessibleButton {
         display: flex;
         align-items: center;
-    }
 
-    .mx_UserMenu_userAvatar {
-        position: relative;
+        .mx_UserMenu_userAvatar {
+            position: relative;
+
+            .mx_BaseAvatar {
+                pointer-events: none; // makes the avatar non-draggable
+            }
+        }
     }
 
     .mx_UserMenu_name {