feat: exec an alert with an error message in case of missing TTS voices

aip_trainer/lambdas/js.py

@@ -65,9 +65,9 @@ function playAudio(text, language) {
             voicesSynth = voices.filter(voice => voice.lang.startsWith(language));
         }
         if (voicesSynth.length === 0) {
-            console.error(`No voice found for language ${voice_lang}/${language}, you should use the Text-To-Speech backend feature...`)
-            throw new Error(`No voice found for language ${voice_lang}/${language}, you should use the Text-To-Speech backend feature...`)
-            alert(`No voice found for language ${voice_lang}/${language}, you should use the Text-To-Speech backend feature...`)
+            msg = `Error: no voice found for language ${voice_lang} / ${language}, you should use the Text-To-Speech backend feature...`
+            alert(msg)
+            throw new Error(msg)
         }
         var utterThis = new SpeechSynthesisUtterance(text);
         utterThis.voice = voicesSynth[0];