perf: replace PaletteService with blurred cover background, bump v3.5.1

pubspec.lock

@@ -741,14 +741,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.2.0"
-  palette_generator:
-    dependency: "direct main"
-    description:
-      name: palette_generator
-      sha256: "4420f7ccc3f0a4a906144e73f8b6267cd940b64f57a7262e95cb8cec3a8ae0ed"
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.3.3+7"
   path:
     dependency: "direct main"
     description: