fix typo

Author: pri-yan-shu

proposals/2026-05-14_pipewire.md

@@ -25,7 +25,7 @@ exposed, which leads to poor experience on Linux (for example,
 
 * There is no hotplug for SoundDevices
 * As mentioned in the "Why" section, PortAudio only lets us route to and from
-  soundcards, and not the input/output of any arbitary program
+  soundcards, and not the input/output of any arbitrary program
 
 ## Goals