cirrus-ci: Remove MSYS2 jobs duplicated with gitlab-ci

cirrus-ci: Remove MSYS2 jobs duplicated with gitlab-ci

- Various developers are reluctant to git Cirrus-CI the permissions
  requested to access their GitHub account.

- When we use the cirrus-run script to trigger Cirrus-CI job from
  GitLab-CI, the GitLab-CI job is restricted to a 1h timeout
  (often not enough).

- Although Cirrus-CI VMs are more powerful than GitLab-CI ones,
  its free plan is limited in 2 concurrent jobs.

- The GitLab-CI MSYS2 jobs are a 1:1 mapping with the Cirrus-CI ones
  (modulo the environment caching).

Reduce the maintenance burden by removing the Cirrus-CI config file,
keeping the GitLab-CI jobs.

Update Yonggang Luo's maintenance file list to the new file, which
use the same environment shell.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230322135721.61138-3-philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit da80f11efeea451eaa00e347f722d867ed9ac5be)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(Mjt: ignore previous changes in .cirrus.yml since it is being removed anyway)