Update FluidAudio version to 0.7.9 (#192)

Updated the version of FluidAudio in the Swift Package Manager section.

### Why is this change needed?
<!-- Explain the motivation for this change. What problem does it solve?
-->

Author: BrandonWeng

README.md

@@ -61,7 +61,7 @@ Add FluidAudio to your project using Swift Package Manager:
 
 ```swift
 dependencies: [
-    .package(url: "https://github.com/FluidInference/FluidAudio.git", from: "0.7.7"),
+    .package(url: "https://github.com/FluidInference/FluidAudio.git", from: "0.7.9"),
 ],
 ```