replaced the depreacted version of reader from the new one

app.py

@@ -6,7 +6,7 @@ import PyPDF2
 def pdf_to_audio(pdf_file):
     pdf_reader = PyPDF2.PdfReader(pdf_file)
     text = ""
-    for page in range(pdf_reader.numPages):
+    for page in range(len(pdf_reader.pages)):
         text += pdf_reader.getPage(page).extractText()
 
     engine = pyttsx3.init()
@@ -24,4 +24,4 @@ with demo:
 
     b1.click(pdf_to_audio, inputs=pdf_file, outputs=text)
 
-demo.launch()
+demo.launch()