TarPackageDeployService: Don't disconnect from installer signals

It looks like the same instance of TarPackageDeployService
may be reused for subsequent application run.
Close the process instead.

Change-Id: I3430404c33c14b1b4f24b728b44b3e54a57e3c9b
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/remotelinux/tarpackagedeploystep.cpp

@@ -177,7 +177,7 @@ void TarPackageDeployService::setFinished()
 {
     m_state = Inactive;
     m_uploader.stop();
-    disconnect(&m_installer, nullptr, this, nullptr);
+    m_installer.close();
     handleDeploymentDone();
 }