vm: fix screenshot timer

Fixes #5541

Author: osy

Services/UTMAppleVirtualMachine.swift

@@ -534,6 +534,7 @@ extension UTMAppleVirtualMachine: VZVirtualMachineDelegate {
                 }
             }
         }
+        try? saveScreenshot()
         state = .stopped
     }
 

Services/UTMQemuVirtualMachine.swift

@@ -415,7 +415,6 @@ extension UTMQemuVirtualMachine {
             throw UTMQemuVirtualMachineError.invalidVmState
         }
         await takeScreenshot()
-        try saveScreenshot()
         try await monitor.qemuStop()
     }
 
@@ -551,6 +550,7 @@ extension UTMQemuVirtualMachine: QEMUVirtualMachineDelegate {
         swtpm = nil
         ioService = nil
         ioServiceDelegate = nil
+        try? saveScreenshot()
         state = .stopped
     }
 

Services/UTMVirtualMachine.swift

@@ -293,7 +293,7 @@ extension UTMVirtualMachine {
         if !isScreenshotSaveEnabled && !isRunningAsDisposible {
             try? deleteScreenshot()
         }
-        return Timer.scheduledTimer(withTimeInterval: kScreenshotPeriodSeconds, repeats: true) { [weak self] timer in
+        let timer = Timer(timeInterval: kScreenshotPeriodSeconds, repeats: true) { [weak self] timer in
             guard let self = self else {
                 timer.invalidate()
                 return
@@ -304,6 +304,8 @@ extension UTMVirtualMachine {
                 }
             }
         }
+        RunLoop.main.add(timer, forMode: .default)
+        return timer
     }
 
     func loadScreenshot() -> PlatformImage? {