Drop some literal types from argparse (add_argument)

These were introduced in python#7329 and they cause false positives
in code that used to be accepted before. There was a false
positive in https://github.com/pycqa/pylint (encountered in
python/mypy#12321) and I also saw
false positives in an internal codebase.

I suggest not using literal types here, since they can be kind of
awkward to annotate in callers that don't pass a literal string.
Rrequiring callers to write annotations like
`Literal["?", "*", "+", "...", "A...", "==SUPPRESS=="]` is not
very user friendly.

Author: JukkaL

stdlib/argparse.pyi

@@ -106,11 +106,8 @@ class _ActionsContainer:
     def add_argument(
         self,
         *name_or_flags: str,
-        action: Literal[
-            "store", "store_const", "store_true", "store_false", "append", "append_const", "count", "help", "version", "extend"
-        ]
-        | type[Action] = ...,
-        nargs: int | Literal["?", "*", "+", "...", "A...", "==SUPPRESS=="] | _SUPPRESS_T = ...,
+        action: str | type[Action] = ...,
+        nargs: int | str | _SUPPRESS_T = ...,
         const: Any = ...,
         default: Any = ...,
         type: Callable[[str], _T] | FileType = ...,