Merge remote-tracking branch 'origin/release/15.0' into v15/dev

# Conflicts:
#	src/Umbraco.Infrastructure/Migrations/Upgrade/V_15_0_0/ConvertBlockEditorPropertiesBase.cs
#	src/Umbraco.Web.UI.Client

tools/Umbraco.JsonSchema/UmbracoCmsSchema.cs

@@ -67,6 +67,7 @@ internal class UmbracoCmsSchema
 
         public required LegacyPasswordMigrationSettings LegacyPasswordMigration { get; set; }
 
+        [Obsolete("Scheduled for removal in v16, dashboard manipulation is now done trough frontend extensions.")]
         public required ContentDashboardSettings ContentDashboard { get; set; }
 
         public required HelpPageSettings HelpPage { get; set; }