Port some KCMs away from deprecated KShortcutsEditor::undoChanges()

undoChanges() has been deprecated in favor of undo() in KF 5.75.

effects/desktopgrid/desktopgrid_config.cpp

@@ -85,8 +85,8 @@ DesktopGridEffectConfig::DesktopGridEffectConfig(QWidget* parent, const QVariant
 
 DesktopGridEffectConfig::~DesktopGridEffectConfig()
 {
-    // If save() is called undoChanges() has no effect
+    // If save() is called undo() has no effect
-    m_ui->shortcutEditor->undoChanges();
+    m_ui->shortcutEditor->undo();
 }
 
 void DesktopGridEffectConfig::save()

effects/invert/invert_config.cpp

@@ -60,7 +60,7 @@ InvertEffectConfig::InvertEffectConfig(QWidget* parent, const QVariantList& args
 InvertEffectConfig::~InvertEffectConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    mShortcutEditor->undoChanges();
+    mShortcutEditor->undo();
 }
 
 void InvertEffectConfig::load()

effects/lookingglass/lookingglass_config.cpp

@@ -81,7 +81,7 @@ LookingGlassEffectConfig::LookingGlassEffectConfig(QWidget* parent, const QVaria
 LookingGlassEffectConfig::~LookingGlassEffectConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    m_ui->editor->undoChanges();
+    m_ui->editor->undo();
 }
 
 void LookingGlassEffectConfig::save()

effects/magnifier/magnifier_config.cpp

@@ -83,7 +83,7 @@ MagnifierEffectConfig::MagnifierEffectConfig(QWidget* parent, const QVariantList
 MagnifierEffectConfig::~MagnifierEffectConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    m_ui->editor->undoChanges();
+    m_ui->editor->undo();
 }
 
 void MagnifierEffectConfig::save()

effects/mouseclick/mouseclick_config.cpp

@@ -65,7 +65,7 @@ MouseClickEffectConfig::MouseClickEffectConfig(QWidget* parent, const QVariantLi
 MouseClickEffectConfig::~MouseClickEffectConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    m_ui->editor->undoChanges();
+    m_ui->editor->undo();
 }
 
 void MouseClickEffectConfig::save()

effects/mousemark/mousemark_config.cpp

@@ -75,7 +75,7 @@ MouseMarkEffectConfig::MouseMarkEffectConfig(QWidget* parent, const QVariantList
 MouseMarkEffectConfig::~MouseMarkEffectConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    m_ui->editor->undoChanges();
+    m_ui->editor->undo();
 }
 
 void MouseMarkEffectConfig::save()

effects/presentwindows/presentwindows_config.cpp

@@ -82,8 +82,8 @@ PresentWindowsEffectConfig::PresentWindowsEffectConfig(QWidget* parent, const QV
 
 PresentWindowsEffectConfig::~PresentWindowsEffectConfig()
 {
-    // If save() is called undoChanges() has no effect
+    // If save() is called undo() has no effect
-    m_ui->shortcutEditor->undoChanges();
+    m_ui->shortcutEditor->undo();
 }
 
 void PresentWindowsEffectConfig::save()

effects/showpaint/showpaint_config.cpp

@@ -53,8 +53,8 @@ ShowPaintEffectConfig::ShowPaintEffectConfig(QWidget *parent, const QVariantList
 
 ShowPaintEffectConfig::~ShowPaintEffectConfig()
 {
-    // If save() is called, undoChanges() has no effect.
+    // If save() is called, undo() has no effect.
-    m_ui->shortcutsEditor->undoChanges();
+    m_ui->shortcutsEditor->undo();
 
     delete m_ui;
 }

effects/thumbnailaside/thumbnailaside_config.cpp

@@ -72,7 +72,7 @@ ThumbnailAsideEffectConfig::ThumbnailAsideEffectConfig(QWidget* parent, const QV
 ThumbnailAsideEffectConfig::~ThumbnailAsideEffectConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    m_ui->editor->undoChanges();
+    m_ui->editor->undo();
 }
 
 void ThumbnailAsideEffectConfig::save()

effects/windowgeometry/windowgeometry_config.cpp

@@ -61,7 +61,7 @@ WindowGeometryConfig::WindowGeometryConfig(QWidget* parent, const QVariantList&
 WindowGeometryConfig::~WindowGeometryConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    myUi->shortcuts->undoChanges();
+    myUi->shortcuts->undo();
 }
 
 void WindowGeometryConfig::save()

effects/zoom/zoom_config.cpp

@@ -126,7 +126,7 @@ ZoomEffectConfig::ZoomEffectConfig(QWidget* parent, const QVariantList& args) :
 ZoomEffectConfig::~ZoomEffectConfig()
 {
     // Undo (only) unsaved changes to global key shortcuts
-    m_ui->editor->undoChanges();
+    m_ui->editor->undo();
 }
 
 void ZoomEffectConfig::save()