public Table getTable() {
    return table;
  }
Create a filter expression for expired files for the `FILE` level. For the `PARTITION` level,
we need to collect the oldest files to determine if the partition is obsolete, so we will not
filter for expired files at the scanning stage

@param expirationConfig expiration configuration
@param expireTimestamp expired timestamp
amoro-ams/src/main/java/org/apache/amoro/server/optimizing/maintainer/IcebergTableMaintainer.java