v4.0.1

Fix compile error for Swift 5.9

Swift 5.9 doesn't support partial consume, so we have to consume self entirely first, then access its property.

error: 'self' consumed more than once
    public consuming func map<NewOutput>(
                          ^
note: consumed here
        let parse = self._parse
                    ^
note: consumed again here
        return .init(selector: selector) { e in
                               ^

Full Changelog: v4.0.0...v4.0.1