Remove collection of subprocess return code

I don't think it's needed for anything.

src/synthesize.py

@@ -74,7 +74,7 @@ def synth_espeakng(text:str, model:str):
     '''
     if model is not None:
 
-        subprocess.run(['espeak-ng', f'-v{model}', "-w test.wav", text]).returncode
+        subprocess.run(['espeak-ng', f'-v{model}', "-w test.wav", text]) #.returncode
     
         sampling_rate, wav = wavfile.read('test.wav')
         os.remove("test.wav")