vars: delete old var when changing share

When changing a password from non-shared to shared, we want to remove the old one

pkgs/clan-cli/clan_cli/vars/var.py

@@ -46,7 +46,7 @@ class Var:
         except UnicodeDecodeError:
             return "<binary blob>"
 
-    def set(self, value: bytes) -> Path | None:
+    def set(self, value: bytes) -> list[Path]:
         assert self._store is not None
         assert self._generator is not None
         return self._store.set(self._generator, self, value)