Re: ci: Skip minfree file in the cores_backtrace.sh

I looked at v2, focused on the cores_backtrace.sh file selection.

The patch applies cleanly on current master at
8a86aa313a714adc56c74e4b08793e4e6102b5ca.

git diff --check reports no issues, and:

sh -n src/tools/ci/cores_backtrace.sh

reports no syntax issues.

I checked the current Cirrus core-file naming and did not find a configured
name that this pattern would miss. Linux uses /tmp/cores/%e-%s-%p.core,
FreeBSD uses /tmp/cores/%N.%P.core, NetBSD/OpenBSD move *.core files into
the common directory, and macOS uses ${HOME}/cores/core.%P.

I also checked the OpenBSD cores step in the linked Cirrus run:
https://cirrus-ci.com/build/6447813132812288

It ran cores_backtrace.sh, lldb loaded /var/crash/initdb.core, and
thread backtrace all produced a backtrace.

I have not reproduced the original failure locally or run Cirrus CI myself.

Regards,
Ilmar