Bump deps and test fixes

Author: adamyeats

jest-setup.js

@@ -1,2 +1,16 @@
 // Jest setup provided by Grafana scaffolding
 import './.config/jest-setup';
+import { TextEncoder, TextDecoder } from 'util';
+
+global.TextEncoder = TextEncoder;
+global.TextDecoder = TextDecoder;
+
+const mockIntersectionObserver = jest.fn().mockImplementation((arg) => ({
+  observe: jest.fn().mockImplementation((elem) => {
+    arg([{ target: elem, isIntersecting: true }]);
+  }),
+  unobserve: jest.fn(),
+  disconnect: jest.fn(),
+}));
+
+global.IntersectionObserver = mockIntersectionObserver;