ARROW-8848: [Ruby][CI] Fix MSYS2 update error
ARROW-8848: [Ruby][CI] Fix MSYS2 update error

pacman 5.2.1 uses zstd instead of gzip. Upgrading pacman by pacman
from old MSYS2 doesn't work. We need to upgrade pacman manually.

See also: https://github.com/msys2/MSYS2-packages/issues/1960

Closes #7239 from kou/glib-ci-fix-msys2-update

Authored-by: Sutou Kouhei <73218711cdd5d5c30ac66da3cc4d9d9204caf34b@clear-code.com>
Signed-off-by: Sutou Kouhei <73218711cdd5d5c30ac66da3cc4d9d9204caf34b@clear-code.com>

cpcloud/arrow,icexelloss/arrow,cpcloud/arrow,wesm/arrow,laurentgo/arrow,kou/arrow,apache/arrow,cpcloud/arrow,cpcloud/arrow,wesm/arrow,icexelloss/arrow,xhochy/arrow,wesm/arrow,cpcloud/arrow,apache/arrow,laurentgo/arrow,icexelloss/arrow,wesm/arrow,cpcloud/arrow,apache/arrow,laurentgo/arrow,icexelloss/arrow,apache/arrow,apache/arrow,icexelloss/arrow,wesm/arrow,xhochy/arrow,laurentgo/arrow,apache/arrow,xhochy/arrow,kou/arrow,apache/arrow,icexelloss/arrow,kou/arrow,laurentgo/arrow,cpcloud/arrow,kou/arrow,cpcloud/arrow,xhochy/arrow,wesm/arrow,xhochy/arrow,apache/arrow,apache/arrow,xhochy/arrow,icexelloss/arrow,cpcloud/arrow,xhochy/arrow,xhochy/arrow,icexelloss/arrow,wesm/arrow,xhochy/arrow,kou/arrow,laurentgo/arrow,wesm/arrow,apache/arrow,icexelloss/arrow,xhochy/arrow,kou/arrow,cpcloud/arrow,laurentgo/arrow,xhochy/arrow,icexelloss/arrow,kou/arrow,cpcloud/arrow,cpcloud/arrow,laurentgo/arrow,xhochy/arrow,wesm/arrow,wesm/arrow,wesm/arrow,kou/arrow,kou/arrow,wesm/arrow,laurentgo/arrow,xhochy/arrow,apache/arrow,kou/arrow,kou/arrow,cpcloud/arrow,laurentgo/arrow,apache/arrow,icexelloss/arrow,apache/arrow,laurentgo/arrow,laurentgo/arrow,laurentgo/arrow,apache/arrow,wesm/arrow,cpcloud/arrow,xhochy/arrow,icexelloss/arrow,laurentgo/arrow,laurentgo/arrow,xhochy/arrow,kou/arrow,icexelloss/arrow,kou/arrow,wesm/arrow,icexelloss/arrow,kou/arrow