Enable fixed pinecone test (#29027)

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

playwright/e2e/sliding-sync/sliding-sync.spec.ts

@@ -69,11 +69,6 @@ const test = base.extend<{
 });
 
 test.describe("Sliding Sync", () => {
-    test.skip(
-        ({ homeserverType }) => homeserverType === "pinecone",
-        "due to a bug in Pinecone https://github.com/element-hq/dendrite/issues/3490",
-    );
-
     const checkOrder = async (wantOrder: string[], page: Page) => {
         await expect(page.getByRole("group", { name: "Rooms" }).locator(".mx_RoomTile_title")).toHaveText(wantOrder);
     };