autogen.sh emits warnings on ubuntu 22.04

[garlick]

Some modernization might be needed here:

$ ./autogen.sh
Running libtoolize --automake --copy ... 
Running autoreconf --verbose --install
autoreconf: export WARNINGS=
autoreconf: Entering directory '.'
autoreconf: configure.ac: not using Gettext
autoreconf: running: aclocal -I config
autoreconf: configure.ac: tracing
autoreconf: running: libtoolize --copy
autoreconf: configure.ac: not using Intltool
autoreconf: configure.ac: not using Gtkdoc
autoreconf: running: aclocal -I config
autoreconf: running: /usr/bin/autoconf
configure.ac:12: warning: The macro `AC_CANONICAL_SYSTEM' is obsolete.
configure.ac:12: You should run autoupdate.
./lib/autoconf/general.m4:2081: AC_CANONICAL_SYSTEM is expanded from...
configure.ac:12: the top level
configure.ac:19: warning: 'AM_CONFIG_HEADER': this macro is obsolete.
configure.ac:19: You should use the 'AC_CONFIG_HEADERS' macro instead.
./lib/autoconf/general.m4:2434: AC_DIAGNOSE is expanded from...
aclocal.m4:781: AM_CONFIG_HEADER is expanded from...
configure.ac:19: the top level
configure.ac:72: warning: The macro `AC_PROG_CC_C99' is obsolete.
configure.ac:72: You should run autoupdate.
./lib/autoconf/c.m4:1659: AC_PROG_CC_C99 is expanded from...
configure.ac:72: the top level
configure.ac:77: warning: The macro `AC_FD_CC' is obsolete.
configure.ac:77: You should run autoupdate.
./lib/autoconf/general.m4:399: AC_FD_CC is expanded from...
lib/m4sugar/m4sh.m4:692: _AS_IF_ELSE is expanded from...
lib/m4sugar/m4sh.m4:699: AS_IF is expanded from...
./lib/autoconf/general.m4:2249: AC_CACHE_VAL is expanded from...
config/am_check_pymod.m4:3: AM_CHECK_PYMOD is expanded from...
lib/m4sugar/m4sh.m4:699: AS_IF is expanded from...
configure.ac:77: the top level
configure.ac:122: warning: The macro `AC_HEADER_STDC' is obsolete.
configure.ac:122: You should run autoupdate.
./lib/autoconf/headers.m4:704: AC_HEADER_STDC is expanded from...
configure.ac:122: the top level
configure.ac:152: warning: The macro `AC_HELP_STRING' is obsolete.
configure.ac:152: You should run autoupdate.
./lib/autoconf/general.m4:204: AC_HELP_STRING is expanded from...
config/ac_pkgconfig.m4:3: AC_PKGCONFIG is expanded from...
configure.ac:152: the top level
autoreconf: running: /usr/bin/autoheader
autoreconf: running: automake --add-missing --copy --no-force
configure.ac:67: installing 'config/compile'
configure.ac:12: installing 'config/config.guess'
configure.ac:12: installing 'config/config.sub'
configure.ac:17: installing 'config/install-sh'
configure.ac:17: installing 'config/missing'
parallel-tests: installing 'config/test-driver'
src/imp/Makefile.am: installing 'config/depcomp'
src/libtomlc99/Makefile.am:54: warning: EXTRA_DIST multiply defined in condition TRUE ...
src/libtomlc99/Makefile.am:12: ... 'EXTRA_DIST' previously defined here
autoreconf: Leaving directory '.'
Now run ./configure.