Remove QObjectRef in favor of QPointer (#4666)

* replace usage of QObjectRef with QPointer

* delete QObjectRef class

* inlucde QPointer header

* Add changelog entry

* use isNull() instead of ! data()

---------

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/providers/irc/IrcServer.cpp

@@ -11,9 +11,9 @@
 #include "providers/twitch/TwitchIrcServer.hpp"  // NOTE: Included to access the mentions channel
 #include "singletons/Settings.hpp"
 #include "util/IrcHelpers.hpp"
-#include "util/QObjectRef.hpp"
 
 #include <QMetaEnum>
+#include <QPointer>
 
 #include <cassert>
 #include <cstdlib>
@@ -151,7 +151,7 @@ void IrcServer::initializeConnection(IrcConnection *connection,
                 [[fallthrough]];
             case IrcAuthType::Pass:
                 this->data_->getPassword(
-                    this, [conn = new QObjectRef(connection) /* can't copy */,
+                    this, [conn = new QPointer(connection) /* can't copy */,
                            this](const QString &password) mutable {
                         if (*conn)
                         {