fix: handle missing pty module on Windows with graceful error message

src/snek/system/terminal.py

@@ -1,6 +1,11 @@
 import asyncio
 import os
-import pty
+
+try:
+    import pty
+except Exception as ex:
+    print("You are not able to run a terminal. See error:")
+    print(ex)
 import subprocess
 
 commands = {