[Backport release/3.8] gdal_sieve.py/gdalattachpct.py/gdalcompare.py/gdalmove.py: make sure --version and --help return 0 error code (fixes #8717)

[Backport release/3.8] gdal_sieve.py/gdalattachpct.py/gdalcompare.py/gdalmove.py: make sure --version and --help return 0 error code (fixes #8717) #8479