revert: drop the alert feed widget, the notification center replaces it

plugins/alerts/tests/frontend/activate.test.tsx

@@ -148,50 +148,3 @@ describe("the alerts panel", () => {
     );
   });
 });
-
-describe("the alert feed homepage widget", () => {
-  it("registers under the 2.8 widget id", async () => {
-    rendered = await renderWithApp(plugin, { manifest, locales });
-    expect(rendered.registered.extensions("homepage.widgets")).toEqual([
-      "alert_feed",
-    ]);
-  });
-
-  it("shows unread alerts and marks one read", async () => {
-    const { api, calls } = stubApi();
-    rendered = await renderWithApp(plugin, { manifest, locales, api });
-    const view = rendered.renderExtension(
-      "homepage.widgets",
-      "alert_feed",
-      "view",
-      {
-        widget: { title: null },
-        config: { maxItems: 5, showRead: false },
-      },
-    );
-    await waitFor(() =>
-      expect(view.textContent).toContain("Certificate renewal failed"),
-    );
-    expect(calls).toContainEqual(["GET", "/items?unread=true&limit=5"]);
-    fireEvent.click(view.querySelector('[title="Mark as read"]')!);
-    await waitFor(() =>
-      expect(calls).toContainEqual([
-        "POST",
-        "/items/read",
-        { ids: [2], read: true },
-      ]),
-    );
-  });
-
-  it("reads the 2.8 showAcknowledged option", async () => {
-    const { api, calls } = stubApi();
-    rendered = await renderWithApp(plugin, { manifest, locales, api });
-    rendered.renderExtension("homepage.widgets", "alert_feed", "view", {
-      widget: {},
-      config: { maxItems: 3, showAcknowledged: true },
-    });
-    await waitFor(() =>
-      expect(calls).toContainEqual(["GET", "/items?limit=3"]),
-    );
-  });
-});