Fix crash in spotlight mode while connecting

Because we were hiding even the local participant during initial connection, there would be no participants, and therefore nothing to put in the spotlight. The designs don't really tell us what the connecting state should look like, so I've taken the liberty of restoring it to its former glory of showing the local participant immediately.

src/grid/Grid.tsx

@@ -268,12 +268,13 @@ export function Grid<
       ) as HTMLCollectionOf<HTMLElement>;
       for (const slot of slots) {
         const id = slot.getAttribute("data-id")!;
-        result.push({
-          ...tiles.get(id)!,
-          ...offset(slot, gridRoot),
-          width: slot.offsetWidth,
-          height: slot.offsetHeight,
-        });
+        if (slot.offsetWidth > 0 && slot.offsetHeight > 0)
+          result.push({
+            ...tiles.get(id)!,
+            ...offset(slot, gridRoot),
+            width: slot.offsetWidth,
+            height: slot.offsetHeight,
+          });
       }
     }