dankbar: fix widget registration during visibility changes

fixes #1956

quickshell/Modules/Settings/DesktopWidgetBrowser.qml

@@ -110,6 +110,8 @@ FloatingWindow {
     color: Theme.surfaceContainer
     visible: false
 
+    onClosed: hide()
+
     onVisibleChanged: {
         if (visible) {
             updateFilteredWidgets();

quickshell/Modules/Settings/PluginBrowser.qml

@@ -482,6 +482,8 @@ FloatingWindow {
     color: Theme.surfaceContainer
     visible: false
 
+    onClosed: hide()
+
     onVisibleChanged: {
         if (visible) {
             pendingInstallHandled = false;

quickshell/Modules/Settings/WidgetSelectionPopup.qml

@@ -115,6 +115,8 @@ FloatingWindow {
     color: blurActive ? Theme.withAlpha(Theme.surfaceContainer, 0) : Theme.surfaceContainer
     visible: false
 
+    onClosed: hide()
+
     onVisibleChanged: {
         if (visible) {
             Qt.callLater(() => {

quickshell/Modules/Settings/Widgets/AppBrowserPopup.qml

@@ -26,6 +26,8 @@ FloatingWindow {
     color: "transparent"
     visible: false
 
+    onClosed: hide()
+
     WindowBlur {
         targetWindow: root
         blurX: 0