Remove 3rd stage of migration

src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/Migrations/20260522092303_AddNormalizedUsername.cs

@@ -16,7 +16,8 @@ namespace Jellyfin.Server.Implementations.Migrations
                 table: "Users",
                 type: "TEXT",
                 maxLength: 255,
-                nullable: true);
+                nullable: false,
+                defaultValue: string.Empty);
         }
 
         /// <inheritdoc />

src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/Migrations/20260522092305_UpdateNormalizedUsername.cs

@@ -1,31 +0,0 @@
-using Jellyfin.Database.Implementations;
-using Microsoft.EntityFrameworkCore.Infrastructure;
-using Microsoft.EntityFrameworkCore.Migrations;
-
-#nullable disable
-
-namespace Jellyfin.Server.Implementations.Migrations
-{
-    /// <inheritdoc />
-    [DbContext(typeof(JellyfinDbContext))]
-    [Migration("20260522092305_UpdateNormalizedUsername")]
-    public partial class UpdateNormalizedUsername : Migration
-    {
-        /// <inheritdoc />
-        protected override void Up(MigrationBuilder migrationBuilder)
-        {
-            // this is the 3rd part of the NormalizedUsername migration.
-            migrationBuilder.AlterColumn<string>(
-                name: "NormalizedUsername",
-                table: "Users",
-                type: "TEXT",
-                maxLength: 255,
-                nullable: false);
-        }
-
-        /// <inheritdoc />
-        protected override void Down(MigrationBuilder migrationBuilder)
-        {
-        }
-    }
-}