Add ref support to retrieve runtime & architecture in findLambdas

[JeremyJacquemont]

What does this PR do?

This PR allows to handle correctly runtime and architecture values if these values use Ref intrinsic function.

Motivation

We needed to override findLambdas to handle our usage, this may be useful to others.

Testing Guidelines

Tested by unit tests and deployments in our environments.

Additional Notes

N/A

Types of changes

• [X] Bug fix
• [ ] New feature
• [ ] Breaking change
• [ ] Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• [X] This PR's description is comprehensive
• [ ] This PR contains breaking changes that are documented in the description
• [ ] This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• [ ] This PR impacts documentation, and it has been updated (or a ticket has been logged)
• [X] This PR's changes are covered by the automated tests
• [ ] This PR collects user input/sensitive content into Datadog