Fix errors

backend/src/hatchling/metadata/core.py

@@ -4,8 +4,8 @@
 import sys
 from contextlib import suppress
 from copy import deepcopy
-from typing import TYPE_CHECKING, Any, Generic, cast
 from functools import cached_property
+from typing import TYPE_CHECKING, Any, Generic, cast
 
 from hatchling.metadata.utils import (
     format_dependency,
@@ -100,7 +100,7 @@ def core_raw_metadata(self) -> dict[str, Any]:
     @cached_property
     def dynamic(self) -> list[str]:
         # Here we maintain a copy of the dynamic fields from `self.core raw metadata`.
-        # This property should never be mutated. In contrast, the fields in 
+        # This property should never be mutated. In contrast, the fields in
         # `self.core.dynamic` are depopulated on the first evaulation of `self.core`
         # or `self.version` as the actual values are computed.
         dynamic = self.core_raw_metadata.get('dynamic', [])
@@ -391,7 +391,7 @@ def name(self) -> str:
         return normalize_project_name(self.raw_name)
 
     @cached_property
-    def version(self) -> str:
+    def version(self) -> str | None:
         """
         https://peps.python.org/pep-0621/#version
         """
@@ -404,6 +404,8 @@ def version(self) -> str:
                     'if `version` is in field `project.dynamic`'
                 )
                 raise ValueError(message)
+            else:
+                return None
         else:
             if 'version' in self.dynamic:
                 message = (
@@ -901,6 +903,7 @@ def classifiers(self) -> list[str]:
         verify_classifiers = not os.environ.get('HATCH_METADATA_CLASSIFIERS_NO_VERIFY')
         if verify_classifiers:
             import bisect
+
             import trove_classifiers
 
             known_classifiers = trove_classifiers.classifiers | self._extra_classifiers