fix(slint): drop redundant ARTIST label above the artist name

The small uppercased "ARTIST" eyebrow above the artist name in the
header is redundant — the context (artist page) and the prominent
name below already say it. Removed the Text node and the 6px spacer
that followed.

cc

crates/qbz-slint/ui/artist/ArtistPageView.slint

@@ -352,14 +352,6 @@ export component ArtistPageView inherits Rectangle {
                     spacing: 0px;
                     horizontal-stretch: 1;
 
-                    Text {
-                        text: @tr("ARTIST");
-                        color: Theme.text-muted;
-                        font-size: 10px;
-                        font-weight: Typography.semibold;
-                        letter-spacing: 1.5px;
-                    }
-                    Rectangle { height: 6px; }
                     Text {
                         text: ArtistState.name;
                         color: Theme.text-primary;