PEP 653: Delete out-of-date note and correct tests in mapping pattern…

… translations. (#1895)

pep-0653.rst

@@ -267,7 +267,7 @@ translates to::
 
     if $kind & MATCH_MAPPING == 0:
         FAIL
-    if $value.keys() != $KEYWORD_PATTERNS.keys():
+    if not $value.keys() >= $KEYWORD_PATTERNS.keys():
         FAIL
     # $KEYWORD_PATTERNS is a meta-variable mapping names to variables.
     for $KEYWORD in $KEYWORD_PATTERNS:
@@ -283,7 +283,7 @@ translates to::
 
     if $kind & MATCH_MAPPING == 0:
         FAIL
-    if $value.keys() not >= $KEYWORD_PATTERNS.keys():
+    if not $value.keys() >= $KEYWORD_PATTERNS.keys():
         FAIL:
     # $KEYWORD_PATTERNS is a meta-variable mapping names to variables.
     $tmp = dict($value)
@@ -347,11 +347,6 @@ translates to::
 
 Example: [6]_
 
-.. note::
-
-    ``__match_args__`` is not checked when matching positional-only class patterns,
-    this allows classes to match only positional-only patterns by leaving ``__match_args__`` set to the default value of ``None``.
-
 Class patterns with all keyword patterns::
 
     case ClsName($KEYWORD_PATTERNS):