[Kokoro] Reenable text input

Not urgent, since default sentences are whitelisted. Requires `KOKORO` secret to be added to the Arena Space.

app.py

@@ -453,6 +453,7 @@ OVERRIDE_INPUTS = {
 		3: 1, #speed
 		4: 3000, #trim
 		5: False, #use_gpu; fast enough with multithreaded with CPU
+        6: os.getenv('KOKORO'), #sk
     },
 
     # maskGCT (by amphion)