SQUASH address ruff issues, unused var, double quotes

Author: gsigh

pudb/debugger.py

@@ -776,7 +776,7 @@ def __exit__(self, exc_type, exc_value, exc_traceback):
 
     def press_key_to_return(self):
         with ConsoleSingleKeyReader() as key_reader:
-            key = key_reader.get_single_key()
+            key_reader.get_single_key()
 
 
 class DebuggerUI(FrameVarInfoKeeper):

pudb/lowlevel.py

@@ -334,7 +334,7 @@ def get_single_key(self):
             # special keys (function keys, cursor, keypad) require
             # another call when the first returned '\0' or '\xe0'.
             c = msvcrt.getch()
-            if c in ('\x00', '\xe0'):
+            if c in ("\x00", "\xe0"):
                 c = msvcrt.getch()
             return c