Use autoreconf2.69
autoconf 2.71 in Debian 12 is too different from autoconf 2.69 in Debian 11 and the BIND 9.16 build infrastructure does not easily handle this change. Therefore, use autoreconf2.69 from Debian 12 to keep the build system stable.
Prereq: isc-projects/images!265
Validation pipeline: https://gitlab.isc.org/isc-projects/bind9/-/pipelines/145639
Closes #4270 (closed)
Edited by Michal Nowak