Drop FreeBSD < 14.0-BETA5 <sys/timerfd.h> workarounds
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=273373
https://cgit.freebsd.org/src/commit/?h=releng/14.0&id=7454117918cd
https://lists.freebsd.org/archives/freebsd-stable/2023-October/001533.html
Old -CURRENT, -STABLE, -RELENG snapshots were never supported in ports/.
This reverts commit 4458b6d2d931d462f260dc06fb7b9c7fa1f707aa.
This reverts commit f295903414ccab16e75feb05c851d726deb16713.
This reverts commit d7c830340dbb2e33451d3ad36ea5a707d0d222b6.
This reverts commit 572560076d1c987833958524a2bc4a60a1700287.
This reverts commit f4c28b489119fb134e7873047aea1aa643219d70.
This reverts commit 163928669d74be3a5d8a307b6a03abd06bf55cd6.
This reverts commit b8948f86c12cfe8a24ba203634e3a1572eab4ba8.
This reverts commit 5e70841f87b2d316acc170b0f550e4eab205b6e2.
This reverts commit 600ca97fd58482c907708888a7af879219540a79.
(cherry picked from commit 19ba14bcd81efcbd35a6fedf6d6c75e48432172b)