test(import): add themer url import to cli-test-studio to hit the url handler code path in tests

Author: kbrabrand

packages/@sanity/cli/test/__fixtures__/cli-test-studio/sanity.config.ts

@@ -1,3 +1,4 @@
+import {theme} from 'https://themer.sanity.build/api/hues'
 import {defineConfig} from 'sanity'
 import {structureTool} from 'sanity/structure'
 
@@ -11,4 +12,5 @@ export default defineConfig({
   plugins: [structureTool()],
   logo: MyLogo,
   schema,
+  theme,
 })