remove dotcom's vercel.json (#2689)

It is not used anymore

### Change Type

- [x] `internal` — Any other changes that don't affect the published
package

apps/dotcom/vercel.json

@@ -1,19 +0,0 @@
-{
-	"headers": [
-		{
-			"source": "/assets/(.*)",
-			"headers": [
-				{
-					"key": "Cache-Control",
-					"value": "public,max-age=31536000,immutable"
-				}
-			]
-		}
-	],
-	"rewrites": [
-		{
-			"source": "/(.*)",
-			"destination": "/"
-		}
-	]
-}