fixes for tags infrastructure PR

src/borg/item.pyi

@@ -47,6 +47,10 @@ class ArchiveItem(PropDict):
     @comment.setter
     def comment(self, val: str) -> None: ...
     @property
+    def tags(self) -> List[str]: ...
+    @tags.setter
+    def tags(self, val: List[str]) -> None: ...
+    @property
     def chunker_params(self) -> Tuple: ...
     @chunker_params.setter
     def chunker_params(self, val: Tuple) -> None: ...

src/borg/upgrade.py

@@ -161,4 +161,5 @@ class UpgraderFrom12To20:
             new_metadata["command_line"] = join_cmd(getattr(metadata, "cmdline"))
         if hasattr(metadata, "recreate_cmdline"):
             new_metadata["recreate_command_line"] = join_cmd(getattr(metadata, "recreate_cmdline"))
+        new_metadata["tags"] = []
         return new_metadata