style: Loosen restore_snapshot() typing (#504)

lib/charms/vault_k8s/v0/vault_client.py

@@ -12,6 +12,7 @@
 from abc import abstractmethod
 from dataclasses import dataclass
 from enum import Enum
+from io import IOBase
 from typing import List, Protocol
 
 import hvac
@@ -404,7 +405,7 @@ def create_snapshot(self) -> requests.Response:
         """Create a snapshot of the Vault data."""
         return self._client.sys.take_raft_snapshot()
 
-    def restore_snapshot(self, snapshot: bytes) -> requests.Response:
+    def restore_snapshot(self, snapshot: IOBase) -> requests.Response:
         """Restore a snapshot of the Vault data.
 
         Uses force_restore_raft_snapshot to restore the snapshot

src/charm.py

@@ -1342,7 +1342,7 @@ def _restore_vault(self, snapshot: StreamingBody) -> bool:
             # hvac vault client expects bytes or a file-like object to restore the snapshot
             # StreamingBody implements the read() method
             # so it can be used as a file-like object in this context
-            response = vault.restore_snapshot(snapshot)  # type: ignore[arg-type]
+            response = vault.restore_snapshot(snapshot)
         except VaultClientError as e:
             logger.error("Failed to restore snapshot: %s", e)
             return False