CircleCI: Switch to modern Docker images and Go 1.17
CircleCI: Switch to modern Docker images and Go 1.17

We have been seeing deprecation messages and the older Go 1.13 keeps us
from upgrading to u-root 0.9.0 due to usage of `io.ReadAll`.

Remove working dir and env vars, and actually run `ineffassign` in
the clean-code job.

See also https://discuss.circleci.com/t/legacy-convenience-image-deprecation/41034

Signed-off-by: Daniel Maslowski <59bd0a3ff43b32849b319e645d4798d8a5d1e889@orangecms.org>

linuxboot/fiano