[plugin] Use Swift SubProcess instead of Process when it will be available

[sebsto]

Expected behavior

The Plugins/AWSLambdaPackager/PluginUtils.swift struct should use SubProcess instead of Foundation's Process

https://github.com/apple/swift-foundation/blob/main/Proposals/0007-swift-subprocess.md

Actual behavior

The struct uses Process

Steps to reproduce

n/a

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

n/a

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

main

Swift version

= 6.x

Amazon Linux 2 docker image version

No response

[sebsto]

Project is available, waiting for a 1.0 version (or at least a beta) to not depend on their main branch
https://github.com/swiftlang/swift-subprocess

[sebsto]

Version 0.1 has been published. I propose to use that version when refactoring the archive plugin