Drop autoreconf CI job
In BIND 9.16, we don't need to run autoreconf, because ./configure et al. are part of the source tree. It's nothing more than a check to see if the build configuration can be built.
Sparked by discussion in !8229 (comment 397156).
Note: The docs
job still has autoreconf2.69 -fi
. I don't know if/how this can be dropped.