fix: fix mypy errors

Author: jaya-krishnan-sr

src/dicomweb_client/uri.py

@@ -638,7 +638,7 @@ def _validate_uid(uid: str, permissive: bool) -> None:
         if _REGEX_UID.fullmatch(uid) is None:
             raise ValueError(f'UID {uid!r} must match regex {_REGEX_UID!r} in '
                              'conformance with the DICOM Standard.')
-    elif permissive and _REGEX_PERMISSIVE_UID.fullmatch(uid) is None:
+    elif _REGEX_PERMISSIVE_UID.fullmatch(uid) is None:
         raise ValueError(f'Permissive mode is enabled. UID {uid!r} must match '
                          f'regex {_REGEX_PERMISSIVE_UID!r}.')