perf(turbo): scope topo task inputs to package.json only

The topo virtual task had no explicit inputs, defaulting to all files.
This caused any source change to cascade cache invalidation through
all dependent packages via ^topo. Since topo is only for dependency
ordering, its hash should only change when dependencies change.

turbo.json

@@ -8,7 +8,8 @@
   },
   "tasks": {
     "topo": {
-      "dependsOn": ["^topo"]
+      "dependsOn": ["^topo"],
+      "inputs": ["package.json"]
     },
     "build": {
       "dependsOn": ["^build"],