Create a CI job that tests that we don't like full Foundation

[fabianfett]

Expected behavior

We should have a CI job that validates that we don't link full Foundation and only link FoundationEssentials.

Actual behavior

N/A

Steps to reproduce

N/A

If possible, minimal yet complete reproducer code (or URL to code)

No response

What version of this project (swift-aws-lambda-runtime) are you using?

N/A

Swift version

N/A

Amazon Linux 2 docker image version

No response

[sebsto]

Work in progress on the event library
swift-server/swift-aws-lambda-events#81

[sebsto]

Fixed by #441