Update prompts.py

Get rid of spurious newline after the output prompt (Out[n]: ) in cases where prompt_toolkit is not used (e.g. running ipython inside Emacs)

IPython/terminal/prompts.py

@@ -71,4 +71,4 b' class RichPromptDisplayHook(DisplayHook):'
             if self.shell.pt_cli:
                 self.shell.pt_cli.print_tokens(tokens)
             else:
-                print(*(s for t, s in tokens), sep='')
+                sys.stdout.write(''.join(s for t, s in tokens))