WIP: Pass environment when finding deployment variables

What does this MR do?

Passes an environment object when generating CI variables instead of just passing the environment name. This is required for #52494 (closed), where we will generate Kubernetes namespaces based on the environment (instead of using the same namespace for all environments).

EE counterpart: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/13802

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Performance and testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team