fix (build system): add handling of wrong cbor data passed to SuitTag

Signed-off-by: Robert Stypa <[email protected]>

suit_generator/suit/types/common.py

@@ -674,7 +674,7 @@ class SuitTag(SuitObject):
     def from_cbor(cls, cbstr: bytes) -> SuitTag:
         """Restore SUIT representation from passed CBOR."""
         cbor = cls.deserialize_cbor(cbstr)
-        if cls._metadata.tag.value != cbor.tag:
+        if not hasattr(cbor, 'tag') or cls._metadata.tag.value != cbor.tag:
             raise ValueError(f"CBOR tag not found in: {cbor}")
         return cls(cbor2.CBORTag(cbor.tag, cls._metadata.children[0].from_cbor(cls.serialize_cbor(cbor.value))))