[Package.swift] Don't lock Nimble version to exact v5.0.0
[Package.swift] Don't lock Nimble version to exact v5.0.0

Quick/Quick,dgdosen/Quick,jeffh/Quick,phatblat/Quick,Quick/Quick,Quick/Quick,phatblat/Quick,dgdosen/Quick,DanielAsher/Quick,dgdosen/Quick,phatblat/Quick,Quick/Quick,phatblat/Quick,DanielAsher/Quick,jeffh/Quick,jeffh/Quick