chore: import upstream snapshot with attribution

packages/variable-engine/variable-core/src/utils/toDisposable.tsx

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
+ * SPDX-License-Identifier: MIT
+ */
+
+import { Subscription } from 'rxjs';
+import { Disposable } from '@flowgram.ai/utils';
+
+/**
+ * Convert rxjs subscription to disposable
+ * @param subscription - The rxjs subscription
+ * @returns The disposable
+ */
+export function subsToDisposable(subscription: Subscription): Disposable {
+  return Disposable.create(() => subscription.unsubscribe());
+}