Snapshot restore fails when pgsql_tmp* directories exist in PGDATA #10398

During volume snapshot restore, the PGDATA cleanup step fails with "directory not empty" when non-empty directories matching pgsql_tmp* exist in the data directory.

This happens because RemoveRestoreExcludedFiles (from the machinery library) uses os.Remove to delete paths matched by the pgsql_tmp* glob pattern, which only works for files and empty directories. Extensions loaded via shared_preload_libraries (e.g. vchord) can create directories like pgsql_tmp_vchord_sampling/ in PGDATA during recovery, and the standard PostgreSQL pgsql_tmp/ directory may also contain temporary files.

Example error:

"msg":"restore error","error":"error while cleaning up the recovered PGDATA: remove /var/lib/postgresql/data/pgdata/pgsql_tmp_vchord_sampling: directory not empty"

Per PostgreSQL documentation, all pgsql_tmp* paths are ephemeral runtime artifacts that are excluded from pg_basebackup and cleaned up automatically on startup. They should be removed unconditionally during restore cleanup, regardless of whether they are files or directories.

The fix needs to go in the machinery repository: cloudnative-pg/machinery#217