fix deepgram and playht has white noise from begining of cache audio

lib/utils.js

@@ -35,6 +35,7 @@ function makeFilePath({vendor, key, salt = '', renderForCaching = false}) {
 
 function getFileExtension({vendor, renderForCaching = false}) {
   const mp3Extension = 'mp3';
+  const wavExtension = 'wav';
   const r8Extension = 'r8';
 
   switch (vendor) {
@@ -45,15 +46,20 @@ function getFileExtension({vendor, renderForCaching = false}) {
       } else {
         return mp3Extension;
       }
-    case 'deepgram':
     case 'elevenlabs':
     case 'rimelabs':
-    case 'playht':
       if (renderForCaching || JAMBONES_DISABLE_TTS_STREAMING) {
         return mp3Extension;
       } else {
         return r8Extension;
       }
+    case 'playht':
+    case 'deepgram':
+      if (renderForCaching || JAMBONES_DISABLE_TTS_STREAMING) {
+        return mp3Extension;
+      } else {
+        return wavExtension;
+      }
     case 'nuance':
     case 'nvidia':
     case 'verbio':