fix DataSyncService.syncNodeData removal of non-existent keys

DataSyncService.syncNodeData now ignores removedNodeKeys that do not exist in the nodeData Array

Author: WalterNorthwoods

projects/gojs-angular/package.json

@@ -1,6 +1,6 @@
 {
   "name": "gojs-angular",
-  "version": "2.0.8",
+  "version": "2.0.9",
   "peerDependencies": {
     "@angular/common": "^18.0.0",
     "@angular/core": "^18.0.0"

projects/gojs-angular/src/lib/data-sync.service.ts

@@ -55,7 +55,8 @@ export class DataSyncService {
         const removals = changes.removedNodeKeys.map(key => keyIdxMap.get(key)) as number[];
         removals.sort((a, b) => a - b);
         for (let i = removals.length - 1; i >= 0; i--) {
-          draft.splice(removals[i], 1);
+          const idx = removals[i];
+          if (idx !== undefined) draft.splice(idx, 1);
         }
       }
     });