Fix ESLint import resolution errors in dummy app (#1793)

Disable import/no-unresolved rule for spec/dummy/** files since the dummy
app dependencies are managed separately and may not be installed during
linting.

Author: justin808

eslint.config.ts

@@ -159,6 +159,13 @@ const config = tsEslint.config([
       'react/prop-types': 'off',
     },
   },
+  {
+    files: ['spec/dummy/**/*'],
+    rules: {
+      // The dummy app dependencies are managed separately and may not be installed
+      'import/no-unresolved': 'off',
+    },
+  },
   {
     files: ['**/*.ts{x,}', '**/*.[cm]ts'],