Upgrade our eslint config to the latest (#24647)

* Fix lint error in test-utils.ts

* Upgrade eslint config (and separate projects to support it)

* Handle possibility that req.error could be null

test/test-utils.ts

@@ -34,7 +34,7 @@ export function deleteIndexedDB(dbName: string): Promise<void> {
         };
 
         req.onerror = (ev): void => {
-            reject(new Error(`${Date.now()}: unable to delete indexeddb ${dbName}: ${req.error}`));
+            reject(new Error(`${Date.now()}: unable to delete indexeddb ${dbName}: ${req.error?.message}`));
         };
 
         req.onsuccess = (): void => {