inconsistent behavior in clickhouse-backup, when use --rbac for download no error if RBAC not exists, but restore --rbac return error when RBAC not exists

[Slach]

create logs

2026-06-24 04:22:06.514 INF pkg/server/server.go:355 > /backup/actions call: create_remote --rbac shard1-20260624042202, version=2.7.2
2026-06-24 04:22:06.545 INF pkg/server/server.go:301 > API call HEAD /backup/actions
2026-06-24 04:22:06.545 INF pkg/server/server.go:301 > API call GET /backup/actions
2026-06-24 04:22:06.583 INF pkg/backup/create.go:208 > done createBackupRBAC, size=0B

but restore logs

2026-06-24 04:52:10.609 INF pkg/server/server.go:355 > /backup/actions call: download shard1-20260624042202, version=2.7.2

...

2026-06-24 04:52:17.884 INF pkg/server/server.go:355 > /backup/actions call: restore --schema=1 --rm --rbac   --env=RESTORE_SCHEMA_ON_CLUSTER={cluster} shard1-20260624042202, version=2.7.2

2026-06-24 04:52:18.219 ERR pkg/server/metrics/metrics.go:252 > metrics.ExecuteWithMetrics(restore) return error: restoreRBAC: restoreRBACResolveAllConflicts: walk backup access path: walk backup access path: lstat /var/lib/clickhouse/backup/shard1-20260624042202/access: no such file or directory

[mvanhorn]

Implemented in #1439