Fix various argument of extension modules (#13651)

* Mark various positional-only arguments: These are all positional-only
  arguments in C code using the `METH_O` flag.
* Remove various `*args, **kwargs` arguments that are using the
  `METH_NOARGS` flag in C.

stubs/mysqlclient/MySQLdb/_mysql.pyi

@@ -24,46 +24,46 @@ class connection:
     port: Incomplete
     server_capabilities: Incomplete
     def __init__(self, *args, **kwargs) -> None: ...
-    def _get_native_connection(self, *args, **kwargs): ...
-    def affected_rows(self, *args, **kwargs): ...
+    def _get_native_connection(self): ...
+    def affected_rows(self): ...
     def autocommit(self, on): ...
     def change_user(self, *args, **kwargs): ...
-    def character_set_name(self, *args, **kwargs): ...
-    def close(self, *args, **kwargs): ...
-    def commit(self, *args, **kwargs): ...
-    def dump_debug_info(self, *args, **kwargs): ...
-    def errno(self, *args, **kwargs): ...
-    def error(self, *args, **kwargs): ...
+    def character_set_name(self): ...
+    def close(self): ...
+    def commit(self): ...
+    def dump_debug_info(self): ...
+    def errno(self): ...
+    def error(self): ...
     def escape(self, obj, dict): ...
     def escape_string(self, s): ...
-    def field_count(self, *args, **kwargs): ...
-    def fileno(self, *args, **kwargs): ...
-    def get_autocommit(self, *args, **kwargs): ...
-    def get_character_set_info(self, *args, **kwargs): ...
-    def get_host_info(self, *args, **kwargs): ...
-    def get_proto_info(self, *args, **kwargs): ...
-    def get_server_info(self, *args, **kwargs): ...
-    def info(self, *args, **kwargs): ...
-    def insert_id(self, *args, **kwargs): ...
+    def field_count(self): ...
+    def fileno(self): ...
+    def get_autocommit(self): ...
+    def get_character_set_info(self): ...
+    def get_host_info(self): ...
+    def get_proto_info(self): ...
+    def get_server_info(self): ...
+    def info(self): ...
+    def insert_id(self): ...
     def kill(self, *args, **kwargs): ...
     def next_result(self): ...
     def ping(self): ...
     def query(self, query): ...
-    def read_query_result(self, *args, **kwargs): ...
-    def rollback(self, *args, **kwargs): ...
+    def read_query_result(self): ...
+    def rollback(self): ...
     def select_db(self, *args, **kwargs): ...
     def send_query(self, *args, **kwargs): ...
     def set_character_set(self, charset: str) -> None: ...
     def set_server_option(self, option): ...
-    def shutdown(self, *args, **kwargs): ...
-    def sqlstate(self, *args, **kwargs): ...
-    def stat(self, *args, **kwargs): ...
-    def store_result(self, *args, **kwargs): ...
-    def string_literal(self, obj): ...
-    def thread_id(self, *args, **kwargs): ...
-    def use_result(self, *args, **kwargs): ...
+    def shutdown(self): ...
+    def sqlstate(self): ...
+    def stat(self): ...
+    def store_result(self): ...
+    def string_literal(self, obj, /) -> str: ...
+    def thread_id(self): ...
+    def use_result(self): ...
     def discard_result(self) -> None: ...
-    def warning_count(self, *args, **kwargs): ...
+    def warning_count(self): ...
     def __delattr__(self, name: str, /) -> None: ...
     def __setattr__(self, name: str, value, /) -> None: ...
 
@@ -72,12 +72,12 @@ class result:
     has_next: Incomplete
     def __init__(self, *args, **kwargs) -> None: ...
     def data_seek(self, n): ...
-    def describe(self, *args, **kwargs): ...
+    def describe(self): ...
     def fetch_row(self, *args, **kwargs): ...
     def discard(self) -> None: ...
-    def field_flags(self, *args, **kwargs): ...
-    def num_fields(self, *args, **kwargs): ...
-    def num_rows(self, *args, **kwargs): ...
+    def field_flags(self): ...
+    def num_fields(self): ...
+    def num_rows(self): ...
     def __delattr__(self, name: str, /) -> None: ...
     def __setattr__(self, name: str, value, /) -> None: ...
 
@@ -86,4 +86,4 @@ def debug(*args, **kwargs): ...
 def escape(obj, dict): ...
 def escape_string(s): ...
 def get_client_info(): ...
-def string_literal(obj): ...
+def string_literal(obj, /) -> str: ...