Audio out of band in Unity!

<img width="520" alt="CleanShot 2024-02-14 at 13 11 23@2x" src="https://github.com/rive-app/rive/assets/454182/93fa11fc-276f-40de-9328-15df82f30096">

Also adds export options to audio assets:
![CleanShot 2024-02-14 at 13 14 02@2x](https://github.com/rive-app/rive/assets/454182/e8660cce-12e8-4181-86bb-f52249a9fa9f)

Diffs=
34fff8ea4 Audio out of band in Unity! (#6616)

Co-authored-by: Luigi Rosso <luigi-rosso@users.noreply.github.com>
diff --git a/.rive_head b/.rive_head
index 44802f1..b535eea 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-61f553d6d079a00c264c8668c07762aee46b9720
+34fff8ea44e3d30fb68912af71d35a808a2f8332
diff --git a/include/rive/assets/audio_asset.hpp b/include/rive/assets/audio_asset.hpp
index d1de305..4e00ce5 100644
--- a/include/rive/assets/audio_asset.hpp
+++ b/include/rive/assets/audio_asset.hpp
@@ -19,6 +19,7 @@
 #endif
 
     rcp<AudioSource> audioSource() { return m_audioSource; }
+    void audioSource(rcp<AudioSource> source) { m_audioSource = source; }
 
 private:
     rcp<AudioSource> m_audioSource;
diff --git a/include/rive/audio/audio_source.hpp b/include/rive/audio/audio_source.hpp
index 834741e..b38984b 100644
--- a/include/rive/audio/audio_source.hpp
+++ b/include/rive/audio/audio_source.hpp
@@ -2,7 +2,6 @@
 #ifndef _RIVE_AUDIO_SOURCE_HPP_
 #define _RIVE_AUDIO_SOURCE_HPP_
 
-#include "miniaudio.h"
 #include "rive/refcnt.hpp"
 #include "rive/span.hpp"
 #include "rive/simple_array.hpp"