fix: str enum in run entrypoint (breaking change in Python3.11)

- use enum.auto in the printing utility to ensure that enum values are displayed correctly in str formatting (due to a change in Python 3.11, the enum name was displayed instead of the str value).

mhubio/utils/printing.py

@@ -9,9 +9,9 @@
 -------------------------------------------------
 """
 
-from enum import Enum
+import enum
 
-class f(str, Enum):
+class f(enum.auto):
     chead       = '\033[95m'
     cyan        = '\033[96m'
     cgray       = '\033[30m'