refactor: simplify text validation

Replace explicit text validation with simpler 'if text:' check that handles
all falsy cases (None, empty string, whitespace) while maintaining the same
functionality.

app.py

@@ -208,7 +208,7 @@ def transcribe_and_stream(inputs, model_name="groq_whisper", show_info="show_inf
 
 
 def aya_speech_text_response(text):
-    if text is not None and text!="":
+    if text:
         stream = audio_response_client.chat_stream(message=text,preamble=AUDIO_RESPONSE_PREAMBLE, model=AYA_MODEL_NAME)
         output = ""
 
@@ -236,7 +236,7 @@ def clean_text(text, remove_bullets=False, remove_newline=False):
 def convert_text_to_speech(text, language="english"):
     
     # do language detection to determine voice of speech response
-    if text is not None and text!="":
+    if text:
         # clean text before doing language detection
         cleaned_text = clean_text(text, remove_bullets=True, remove_newline=True)
         text_lang_code = predict_language(cleaned_text)