Circleci update

[th-2021]

Update circleci to use buildkit and large model.

[kkimurak]

Generally looks good. I think it would be better to cleanup git log so that only contains commits for .circleci/config.yml

$ git switch circleci-update

# show changes 
$ git log --oneline master..circleci-update -- .circleci/config.yml
f0665168 (th-2021/multistage) do a standard build for comparison
2de835ee change back to better match master
0fa2518f simplify
738eecd0 add image
d7225209 set buildkit variable
05622753 add buildkit parameter
9a9ede57 use buildkit
6944ffdf remove parallelism; upgrade docker orb
8362e0ec add parallelism
69af74d0 add MAX_OLD_SPACE=8192
d9f882d5 set larger resource class; change to buildx; all for th-2021

$ git reset --hard master

# apply each commits - we need to reverse display order as newer commit comes first by default
# rev-list is used to show only full commit hash instead of log
$ git rev-list master..circleci-update --reverse -- .circleci/ | xargs git cherry-pick

# Conflict may occurs when cherry-picking 2de835ee
# as it contains changes to assets/runtime/function and Dockerfile.multistage
# Simply ignore here
$ git reset Dockerfile.multistage assets/runtime/function

# Continue and cherry-pick the remaining commits
$ git cherry-pick --continue

# Now, commit history for branch circleci-update only contains changes to .circleci/config.yml
# Push it
$ git push --force

[th-2021]

@kkimurak fixed it.

[sachilles]

LGTM

[sachilles]

@th-2021 Sorry for being late. Thanks for your contribution.