For working on initial changes to postgres beta versions make the version check in `./configure` default, but optional.
Normal users will still get the postgres version check error when building on other postgres versions, however, advanced users can use this flag to force configure to pass and find the compilation errors Citus would run into.
Use of the flag is not advised for users not understanding what this does.
When building packages on ubuntu jammy, we started to see some warnings.
autoreconf: warning: autoconf input should be named 'configure.ac', not
'configure.in'