Mk/bsd.port.mk: bump minimal FreeBSD version to 12.3
mail/exim: remove patch specific for 12.2
The patch converts exim to use poll() instead of select().
[rene] no mention about 12.3 but needs to be verified
Mk/bsd.port.mk: update an example
sysutils/lsof: drop support for ancient FreeBSD releases.
multimedia/ustreamer: remove inline patch for 12.2
x11/wayland-logout: remove support for FreeBSD < 12.3
sysutils/bhyve+: remove support for FreeBSD 12.2
databases/clickhouse: remove support for FreeBSD 12.2
databases/mariadb106-server: remove support for FreeBSD 12.2
devel/cvsd: no need to test for FreeBSD >=5 anymore
devel/imake: no need to support a.out anymore
japanese/kterm: no need to support FreeBSD <= 9
math/igraph: remove support for FreeBSD 12.2
net/onedrive: remove support for FreeBSD 12.2
security/botan110: remove support for FreeBSD 12.[012]
This change should be overruled by the expiration date of the port itself.
security/ipsec-tools: no need to test for FreeBSD >= 11
misc/freebsd-release-manifests: prune 12.2 manifests