chore: Allow grpc-tools build scripts in pnpm config (#143)

## Summary
- pnpm blocks build scripts by default — `grpc-tools` needs its install script to download the native `protoc` binary, causing ENOENT in the regen workflow

## Test plan
- [x] Trigger `regen` workflow manually via `workflow_dispatch` and verify it passes

Author: erezrokah

package.json

@@ -49,5 +49,11 @@
   "dependencies": {
     "google-protobuf": "^4.0.0"
   },
-  "packageManager": "pnpm@10.33.0"
+  "packageManager": "pnpm@10.33.0",
+  "pnpm": {
+    "onlyBuiltDependencies": [
+      "grpc-tools",
+      "protobufjs"
+    ]
+  }
 }