refactor: remove importing & using UIKit in non-ui service

Author: uuidev

Sources/EmojiPicker/Services/EmojiManager.swift

@@ -20,7 +20,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-import UIKit
+import Foundation
 
 /// An abstraction over entity that provides emoji set.
 protocol EmojiManagerProtocol {
@@ -64,8 +64,11 @@ final class EmojiManager: EmojiManagerProtocol {
     }
 
     /// Version of operating system of a device.
+    ///
+    /// It takes major and minor version of a device and returns it as `15.5`.
     private var deviceVersion: Double {
-        return (UIDevice.current.systemVersion as NSString).doubleValue
+        let operatingSystemVersion = ProcessInfo().operatingSystemVersion
+        return Double(operatingSystemVersion.majorVersion) + Double(operatingSystemVersion.minorVersion) / 10
     }
 
     // MARK: - Internal Methods