Try 3.10 grammar more often + remove redundant out()

Say you're attrs and you don't configure target-version. Previously
Black would default to trying every single grammar it has, including the
3.10 grammar. With this PR, now target-version is configured for you
effectively so now get_grammars() is more selective in which grammars it
returns. If any target versions don't support the match statement, the
3.10 grammar won't be tried.

And while in theory a 3.7+ project shoudn't be using 3.10 features,
attrs has a test file which uses match (which fails to parse because the
3.10 grammar isn't selected). To avoid breaking attrs, get_grammars()
will now return the 3.10 grammar as long as *any* the target versions
support match.

The out() call was made redundant by an older PR that prints the
configuration if --verbose is passed.

src/black/__init__.py

@@ -520,8 +520,6 @@ def main(  # noqa: C901
                 for param, value in ctx.default_map.items():
                     out(f"{param}: {value}")
 
-        out(f"Target version: {[v.name.lower() for v in target_version]}", fg="blue")
-
     error_msg = "Oh no! 💥 💔 💥"
     if (
         required_version

src/black/parsing.py

@@ -11,7 +11,7 @@
 else:
     from typing import Final
 
-from black.mode import Feature, TargetVersion, supports_feature
+from black.mode import VERSION_TO_FEATURES, Feature, TargetVersion, supports_feature
 from black.nodes import syms
 from blib2to3 import pygram
 from blib2to3.pgen2 import driver
@@ -52,7 +52,7 @@ def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
     if not target_versions:
         # No target_version specified, so try all grammars.
         return [
-            # Python 3.7+
+            # Python 3.7-3.9
             pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords,
             # Python 3.0-3.6
             pygram.python_grammar_no_print_statement_no_exec_statement,
@@ -72,7 +72,7 @@ def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
     if not supports_feature(target_versions, Feature.ASYNC_KEYWORDS):
         # Python 3.0-3.6
         grammars.append(pygram.python_grammar_no_print_statement_no_exec_statement)
-    if supports_feature(target_versions, Feature.PATTERN_MATCHING):
+    if any(Feature.PATTERN_MATCHING in VERSION_TO_FEATURES[v] for v in target_versions):
         # Python 3.10+
         grammars.append(pygram.python_grammar_soft_keywords)