The key techniques to create a cloud are abstraction and orchestration. We abstract the resources from the underlying physical infrastructure to create our pools, and use orchestration (and automation) to coordinate carving out and delivering a set of resources from the pools to the consumers. As you will see, these two techniques create all the essential characteristics we use to define something as a
"cloud."
Ref: CSA Security Guidelines V4.0

DevOps aims to improve collaboration and integration between development and operations teams, streamlining delivery and enhancing software quality. Reference: [CCSK Study Guide, Domain 10 - DevOps
& DevSecOps]

This is true. Credentials and cryptographic keys must not be embedded in source code or distributed in public facing repositories such as GitHub, because there is a significant chance of discovery and misuse.
Keys need to be appropriately secured and a well- secured public key infrastructure (PKI) is needed to ensure key-management activities are carried out.