…ro backup 2 for ENT"This reverts commit98863ae

    This patch adds compatibility changes for PostgreSQL 18:    - Updated signal handler initialization in pgut.c to use sigaction()      instead of pqsignal(), as pqsignal() now returns void.    - Updated process_block_change() in backup.c to handle the new      RelPathStr structure returned by relpathperm() in v18.    - Updated CreateReplicationSlot_compat() in stream.c to support the      new CreateReplicationSlot() signature introduced in v18.    These changes ensure successful build and runtime behavior with    PostgreSQL 18 while preserving backward compatibility with earlier    versions.

In commit 760162f user-callable CRC functions were added.Since pg_probackup uses pg_crc.c from the PostgreSQL source,this change is leading to the undefined reference to pg_detoast_datum_packed errors during the build.See alsohttps://www.postgresql.org/message-id/flat/ME0P300MB0445018F5C924B2D88983F45B66CA%40ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM

Unfortunately remote mode needs to extend ssh agent protocol, that willbroke backward compatibility.

…s version