Remove "under active development" in XNNPACK (pytorch#6048)

Summary: Pull Request resolved: pytorch#6048

Reviewed By: digantdesai

Differential Revision: D64115305

fbshipit-source-id: 3eb526f395b8eab88e1730a1dee3ee1ea3f32171

docs/source/native-delegates-executorch-xnnpack-delegate.md

@@ -2,10 +2,6 @@
 
 This is a high-level overview of the ExecuTorch XNNPACK backend delegate. This high performance delegate is aimed to reduce CPU inference latency for ExecuTorch models. We will provide a brief introduction to the XNNPACK library and explore the delegate’s overall architecture and intended use cases.
 
-::::{note}
-XNNPACK delegate is currently under active development, and may change in the future
-::::
-
 ## What is XNNPACK?
 XNNPACK is a library of highly-optimized neural network operators for ARM, x86, and WebAssembly architectures in Android, iOS, Windows, Linux, and macOS environments. It is an open source project, you can find more information about it on [github](https://github.com/google/XNNPACK).