gh-139292: avoid extra tailing blank line in python -m inspect -d <target> (#139293)

Signed-off-by: yihong0618 <zouzou0208@gmail.com>

Author: yihong0618

Lib/inspect.py

@@ -3397,7 +3397,7 @@ def _main():
             else:
                 print('Line: {}'.format(lineno))
 
-        print('\n')
+        print()
     else:
         print(getsource(obj))