fix: pg_dump/pg_restore permission errors in backup subcontainer

- Pre-create and chown dump file for postgres user before pg_dump
- Chown volume mountpoint to postgres before initdb on restore
- Add --no-privileges to pg_restore to skip GRANT/REVOKE for missing roles

core/Cargo.toml

@@ -161,7 +161,6 @@ nix = { version = "0.30.1", features = [
   "process",
   "sched",
   "signal",
-  "socket",
   "user",
 ] }
 nom = "8.0.0"