misc/freebsd-pkgbase-15-keys: new port to simplify 15.0-RELEASE upgrades for BETA/RC testers

[dch]

Summary

Requested by: clusteradm, core
Refer to: https://reviews.freebsd.org/D53964
Refer to: 463cec10a5fba0b42db7bf699b21e569f2fd6459

Test Plan

• package builds via make ..

 tar tvf /tmp/usr/ports/misc/freebsd-pkgbase-15-keys/work/pkg/freebsd-pkgbase-15-keys-20251128.pkg
-rw-r--r--  0 root   wheel     937 Jan  1  1970 +COMPACT_MANIFEST
-rw-r--r--  0 root   wheel    3608 Jan  1  1970 +MANIFEST
-rw-r--r--  0 root   wheel     188 Nov 28 08:49 /usr/local/share/licenses/freebsd-pkgbase-15-keys-20251128/catalog.mk
-rw-r--r--  0 root   wheel      81 Nov 28 08:49 /usr/local/share/licenses/freebsd-pkgbase-15-keys-20251128/LICENSE
-rw-r--r--  0 root   wheel      97 Nov 28 08:49 /usr/local/share/licenses/freebsd-pkgbase-15-keys-20251128/BSD2CLAUSE
-rw-r--r--  0 root   wheel    1034 Nov 28 08:49 /etc/pkg/FreeBSD.conf.sample
-rw-r--r--  0 root   wheel      99 Nov 28 08:49 /usr/share/keys/pkgbase-15/trusted/awskms-15
-rw-r--r--  0 root   wheel      99 Nov 28 08:49 /usr/share/keys/pkgbase-15/trusted/backup-signing-15

• but not in poudriere

[dch]

still fails in poudriere

[00:00:21] Failed ports: misc/freebsd-pkgbase-15-keys:install

[pkg.skunkwerks.at] Installing freebsd-pkgbase-15-keys-20251128...
mv: rename /usr/local/etc/pkg/FreeBSD.conf to /usr/local/etc/pkg/FreeBSD.conf.pkgsave: No such file or directory
pkg-static: PRE-INSTALL script failed
pkg-static: Fail to create temporary file for /usr/share/keys/pkgbase-15/trusted/awskms-15:Read-only file system
Original FreeBSD.conf backed up to FreeBSD.conf.pkgsave

• Error code 1

[dch]

Sadly (1) this doesn't build successfully in poudriere and (2) when used via pkg add ... fails to install as it conflicts with FreeBSD-pkg-bootstrap

/etc/pkg/FreeBSD.conf
/usr/sbin/pkg
/usr/share/keys/pkg/trusted/pkg.freebsd.org.2013102301
/usr/share/keys/pkgbase-15/trusted/awskms-15
/usr/share/keys/pkgbase-15/trusted/backup-signing-15
/usr/share/man/man7/pkg.7.gz