manual action required updating from 15.0-ALPHA to 15-STABLE with pkgbase

hello,

during the 15.0-ALPHA period, the packages were published with a version
similar to "15.0.a4.YYYYMMDD".  now that stable/15 has become 15-STABLE,
the packages are published with a version similar to "15.snapYYYYMMDD".

unfortunately, pkg considers "15.0.a4" to be newer than "15.snap", so
you will not see any package updates for those packages, even though
they are available.

to work around this, run "pkg upgrade -f -r FreeBSD-base", which will
forcibly reinstall all packages with the version from the repository.
this should only need to be done once, since there are no "a4" packages
left in the repository.

this only affects people who use the base_latest repository and want to
track 15-STABLE.  if you want to track releng/15.0 instead, switch from
the base_latest repository to the base_release_0 repository.  in that
case, no manual action sould be required.