feat: decorate deprecated symbols (#839)

part of  #760 


---------

Signed-off-by: Souta Kawahara <[email protected]>
Signed-off-by: Jan Kowalleck <[email protected]>
Co-authored-by: Souta Kawahara <[email protected]>
Co-authored-by: Jan Kowalleck <[email protected]>

Author: KAWAHARA-souta

cyclonedx/serialization/__init__.py

@@ -20,18 +20,25 @@
 Set of helper classes for use with ``serializable`` when conducting (de-)serialization.
 """
 
+import sys
 from typing import Any, Optional
 from uuid import UUID
 
 # See https://github.com/package-url/packageurl-python/issues/65
 from packageurl import PackageURL
 from py_serializable.helpers import BaseHelper
 
+if sys.version_info > (3, 13):
+    from warnings import deprecated
+else:
+    from typing_extensions import deprecated
+
 from ..exception.serialization import CycloneDxDeserializationException, SerializationOfUnexpectedValueException
 from ..model.bom_ref import BomRef
 from ..model.license import _LicenseRepositorySerializationHelper
 
 
+@deprecated('Use :class:`BomRef` instead.')
 class BomRefHelper(BaseHelper):
     """**DEPRECATED** in favour of :class:`BomRef`.
 
@@ -88,6 +95,7 @@ def deserialize(cls, o: Any) -> UUID:
             ) from err
 
 
+@deprecated('No public API planned for replacing this,')
 class LicenseRepositoryHelper(_LicenseRepositorySerializationHelper):
     """**DEPRECATED**