Fix infinite redirection in audio dataset tutorial (#2266)

* Fix infinite redirection in audio dataset tutorial

The correct target URL is https://pytorch.org/audio/main/tutorials/audio_datasets_tutorial.html

* Update audio_datasets_tutorial.rst

Author: mthrok

beginner_source/audio_datasets_tutorial.rst

@@ -1,10 +1,10 @@
 Audio Datasets
 ==============
 
-This tutorial has been moved to https://pytorch.org/tutorials/beginner/audio_datasets_tutorial.html
+This tutorial has been moved to https://pytorch.org/audio/stable/tutorials/audio_datasets_tutorial.html
 
 It will redirect in 3 seconds.
 
 .. raw:: html
 
-   <meta http-equiv="Refresh" content="3; url='https://pytorch.org/tutorials/beginner/audio_datasets_tutorial.html'" />
+   <meta http-equiv="Refresh" content="3; url='https://pytorch.org/audio/stable/tutorials/audio_datasets_tutorial.html'" />