Drop the whitespace check the charset pin subsumed

The [a-z0-9_]+ fullmatch landed after the whitespace check and fully
absorbs it: all-whitespace input already fails the strip() check, and
interior whitespace fails the charset with an accurate message. The
empty and lowercase pre-checks stay -- they guard the common mistakes
with materially friendlier messages.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: derek73

nameparser/_locale.py

@@ -36,10 +36,6 @@ def __post_init__(self) -> None:
             raise ValueError(
                 f"Locale.code must be lowercase, got {self.code!r}"
             )
-        if any(c.isspace() for c in self.code):
-            raise ValueError(
-                f"Locale.code must not contain whitespace, got {self.code!r}"
-            )
         # Codes are registry keys (parser_for, third-party packs): every
         # accepted character is supported forever, so pin the charset
         # while relaxing later is still compatible. One separator only --

tests/v2/test_locale.py

@@ -29,8 +29,10 @@ def test_locale_code_must_be_nonempty_lowercase() -> None:
 
 
 def test_locale_code_rejects_whitespace() -> None:
+    # caught by the [a-z0-9_]+ charset pin (a dedicated whitespace check
+    # would be pure redundancy; the charset message is accurate)
     for bad in ("ru ", " ru", "ru\n", "r u"):
-        with pytest.raises(ValueError, match="whitespace"):
+        with pytest.raises(ValueError, match="a-z0-9_"):
             Locale(code=bad, lexicon=Lexicon.empty())