Revert "dankbar: keep blur enabled at opacity-0"

This reverts commit 8a5e7c78fb.

fixes #2750

quickshell/Modules/DankBar/DankBarWindow.qml

@@ -240,7 +240,7 @@ PanelWindow {
         id: barBlur
         visible: false
 
-        readonly property bool barHasTransparency: barWindow._backgroundAlpha < 1
+        readonly property bool barHasTransparency: barWindow._backgroundAlpha > 0 && barWindow._backgroundAlpha < 1
 
         function rebuild() {
             teardown();