[CI][easy] use default tier for Docker lint job
[CI][easy] use default tier for Docker lint job

Docker build was moved away from CircleCI. With only the lint job
remaining, we can use the default smaller tier.

Closes: #4698
Approved by: andll

aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core