Cirrus-CI: restore amd64-gcc12 build/test on main

The Cirrus-CI log length issue was addressed by commit 5f72ceb2c50d
("Cirrus-CI: for *-gcc12, build world with make -s"), and the failure
itself by commit 0c785f06020f ("Fix GoogleTest 1.14.0 import").

This reverts commit 0ed2e7e88984aa4ad01a41e9350c5870b271c0c3.

Reported by: Jose Luis Duran
Sponsored by: The FreeBSD Foundation