* Fix build on Ubuntu 24.04 (noble): drop the libmpdec-dev build dependency there (it was removed from noble) and fall back to the bundled _decimal, matching the existing Debian >= 11 handling. - buildsys-pre-build: unset the MPDEC flag for Ubuntu >= 24 as well as Debian >= 11; bionic/jammy still use system libmpdec. * Skip the expat reparse-deferral tests on Ubuntu 22.04 (jammy): its system expat carries the 2.6 reparse-deferral backport but still reports an older version, so the version-gated test_xml_etree tests (test_flush_reparse_deferral_disabled, test_simple_xml_chunk_1/_5) fail. - buildsys-pre-build: set the XMLREPARSE flag for Ubuntu 22.04. - debian/rules: under XMLREPARSE, apply 06002 and 06004 (the same test removals already applied in the RPM/Alpine builds). bionic/noble are unaffected.