fix(core): use post flush to re-observe nodes after toggling visibility (#1517)

* fix(core): use `post` flush to re-observe nodes after toggling visibility

* chore(changeset): add

* chore(core): cleanup

.changeset/chilly-dragons-collect.md

@@ -0,0 +1,5 @@
+---
+"@vue-flow/core": patch
+---
+
+Use `post` flush timing to re-observe node size when toggling node visibility

packages/core/src/components/Nodes/NodeWrapper.ts

@@ -173,7 +173,7 @@ const NodeWrapper = defineComponent({
             })
           }
         },
-        { immediate: true, flush: 'pre' },
+        { immediate: true, flush: 'post' },
       )
     })