[Swift Package] Add minimum platform version to conform to RxSwift dependency

[frboulais]

Action framework needs to specify its minimum platforms versions to be sure they don't conflict with its dependency ones.

[bobgodwinx]

@frboulais Thanks for the update.

• [ ] Can you please remove d66f5c3 and 02b1a26 from the history. That would be nice 😎

[frboulais]

@bobgodwinx How am I supposed to remove the commits? I can restart the PR if you prefer! 👍

[bobgodwinx]

Use git rebase -- interactive eaf6866 and then add a d in the front of d66f5c3 and 02b1a26 then press esc and then :wq to save. That should do the job.