All the `Package.swift` files from the examples use `path: "."` instead
of `path: "Sources"` which triggers error messages when users add a
`Tests` directory.
* add aws sdk example
* add soto example
* use amazonlinux docker image instead of ubuntu
* dynamically add runtime dependency based on env var
* remove import of Foundation.ProcessInfo
* workaround https://github.com/actions/checkout/issues/1487
Sébastien Stormacq