fix(core): correct id access in useVueFlow (#1483)

* fix(core): correct id access in `useVueFlow`

* chore(changeset): add

.changeset/mean-horses-swim.md

@@ -0,0 +1,5 @@
+---
+"@vue-flow/core": patch
+---
+
+Correct access of options id in `useVueFlow`

packages/core/src/composables/useVueFlow.ts

@@ -30,9 +30,9 @@ export function useVueFlow(idOrOpts?: any): VueFlowStore {
 
   const isOptsObj = typeof idOrOpts === 'object'
 
-  const options = isOptsObj ? idOrOpts : undefined
+  const options = isOptsObj ? idOrOpts : { id: idOrOpts }
 
-  const id = options?.id ?? idOrOpts
+  const id = options.id
   const vueFlowId = scope?.vueFlowId || id
 
   let vueFlow: Injection