test: Disable next build test for turbopack (#64236)

### What?

Skip one test completely

### Why?

To make CI green

### How?


Closes PACK-2921

test/production/app-dir/mangle-reserved/mangle-reserved.test.ts

@@ -5,10 +5,9 @@ createNextDescribe(
   {
     files: __dirname,
   },
-  ({ next, isTurbopack }) => {
-    ;(isTurbopack ? it.skip : it)('should work using cheerio', async () => {
+  ({ next }) => {
+    it('should preserve the name', async () => {
       const $ = await next.render$('/')
-      // eslint-disable-next-line jest/no-standalone-expect
       expect($('p').text()).toBe('AbortSignal')
     })
   }

test/turbopack-build-tests-manifest.json

@@ -6163,6 +6163,13 @@
       "pending": [],
       "flakey": [],
       "runtimeError": false
+    },
+    "test/production/app-dir/mangle-reserved/mangle-reserved.test.ts": {
+      "passed": [],
+      "failed": ["mangle-reserved should preserve the name"],
+      "pending": [],
+      "flakey": [],
+      "runtimeError": false
     }
   },
   "rules": {