arrow

ARROW-15133: [CI] Remove util_checkout.sh and util_cleanup.sh scripts

- `ci/scripts/util_checkout.sh` was used to checkout submodules because `actions/checkout@v2` has removed support for that, but they have restored it since.
- `ci/scripts/util_cleanup.sh` was used to free up disk space on github actions runners, because at that time it was limited to 7GB, from a recent run it looks like the linux runners now have 32GB free space so we can try to disable the cleanup step sparing almost a minute of build time

Closes #11974 from kszucs/checkout

Authored-by: Krisztián Szűcs <szucs.krisztian@gmail.com>
Signed-off-by: Jonathan Keane <jkeane@gmail.com>