[Security] Workflow build.yml is using vulnerable action actions/checkout

The workflow build.yml is referencing action actions/checkout using references v1. However this reference is missing the commit [a6747255bd19d7a757dbdda8c654a9f84db19839](https://github.com/actions/checkout/commits/a6747255bd19d7a757dbdda8c654a9f84db19839) which may contain fix to the some vulnerability.
The vulnerability fix that is missing by actions version could be related to:
(1) CVE fix
(2) upgrade of vulnerable dependency
(3) fix to secret leak and others.
Please consider to update the reference to the action.

Open build.yml and locate its actions/checkout reference, which currently uses v1. Compare it with the commit referenced in the issue and update the workflow action reference accordingly. Done means the workflow no longer uses the vulnerable reference and the build configuration remains valid.

Written by the indexing model from the issue text.