refactor: detach buffer on sound stop and remove unused data member

Author: LoayAhmed304

src/common/systems/audio-system.cpp

@@ -199,6 +199,7 @@ namespace our {
 
     void AudioSystem::stopSound(ALuint source) {
         alSourceStop(source);
+        alSourcei(source, AL_BUFFER, AL_NONE);  // detach buffer so it can be safely deleted
         checkALError("Stopping sound");
     }
 

src/common/systems/audio-system.hpp

@@ -20,8 +20,6 @@ namespace our {
         void update(World* world);
         void destroy();
 
-        std::vector<ALuint> sources;  // List of all AL sources used by this system
-
         // On-demand function to play a sound at a 3D world position (fire-and-forget)
         // Play a sound at a 3D world position (fire-and-forget)
         // - buffer: the AudioBuffer containing the sound data to play