Add Windows support

[soumyamahunt]

This PR works on top of #140, to provide Windows runner support.

Tasks completed by @fwal in #140:

• [x] Resolve correct version
• [x] Download Swift package

Tasks completed in this PR:

• [x] Setup Swift on windows
• [x] GPG signature validation
• [x] Tests

Fixes #132.

[soumyamahunt]

@slashmo @fwal I have made changes for windows setup actions as mentioned in the docs, please review and let me know if any further changes needed.

[fwal]

Hi @soumyamahunt! 👋🏻

Thanks for your contribution, this looks great! Could you remove any changes made in the dist folder? We let GitHub actions and manual builds manage that.

[soumyamahunt]

Hi @soumyamahunt! 👋🏻

Thanks for your contribution, this looks great! Could you remove any changes made in the dist folder? We let GitHub actions and manual builds manage that.

Hi @fwal, the changes to the dist folder are auto-generated and shouldn't impact the action. I pushed these changes since I am using this branch in my swift-package jobs until swift-actions creates a new release with windows support. Removing these changes will break those jobs.

[fwal]

@soumyamahunt This is due to security concerns, I would rather not have the dist folder checked in at all but that's just how actions work 😅 I'll sanitise in another branch and merge this in!