fix: peer edge crash due to no parent or detached node

Author: milaninfy

workspaces/arborist/lib/arborist/build-ideal-tree.js

@@ -1299,6 +1299,7 @@ This is a one-time fix-up, please be patient...
   // virtual root is based on the root project, and allow non-peer parent
   // deps to override, but throw if no preference can be determined.
   async #loadPeerSet (node, required) {
+    const parent = node.parent
     const peerEdges = [...node.edgesOut.values()]
       // we typically only install non-optional peers, but we have to
       // factor them into the peerSet so that we can avoid conflicts
@@ -1311,8 +1312,8 @@ This is a one-time fix-up, please be patient...
         continue
       }
 
-      const parentEdge = node.parent.edgesOut.get(edge.name)
-      const { isProjectRoot, isWorkspace } = node.parent.sourceReference
+      const parentEdge = parent.edgesOut.get(edge.name)
+      const { isProjectRoot, isWorkspace } = parent.sourceReference
       const isMine = isProjectRoot || isWorkspace
       const conflictOK = this.options.force || !isMine && !this.#strictPeerDeps