Remove the unreachable null service provider path from code migrations

Jellyfin.Server/Migrations/JellyfinMigrationService.cs

@@ -183,7 +183,7 @@ internal class JellyfinMigrationService
         }
     }
 
-    public async Task MigrateStepAsync(JellyfinMigrationStageTypes stage, IServiceProvider? serviceProvider)
+    public async Task MigrateStepAsync(JellyfinMigrationStageTypes stage, IServiceProvider serviceProvider)
     {
         var logger = _startupLogger.With(_loggerFactory.CreateLogger<JellyfinMigrationService>()).BeginGroup($"Migrate stage {stage}.");
         ICollection<CodeMigration> migrationStage = (Migrations.FirstOrDefault(e => e.Stage == stage) as ICollection<CodeMigration>) ?? [];
@@ -445,10 +445,10 @@ internal class JellyfinMigrationService
     private class InternalCodeMigration : IInternalMigration
     {
         private readonly CodeMigration _codeMigration;
-        private readonly IServiceProvider? _serviceProvider;
+        private readonly IServiceProvider _serviceProvider;
         private JellyfinDbContext _dbContext;
 
-        public InternalCodeMigration(CodeMigration codeMigration, IServiceProvider? serviceProvider, JellyfinDbContext dbContext)
+        public InternalCodeMigration(CodeMigration codeMigration, IServiceProvider serviceProvider, JellyfinDbContext dbContext)
         {
             _codeMigration = codeMigration;
             _serviceProvider = serviceProvider;

Jellyfin.Server/Migrations/Stages/CodeMigration.cs

@@ -20,19 +20,13 @@ internal class CodeMigration(Type migrationType, JellyfinMigrationAttribute meta
         return Metadata.Order.ToString("yyyyMMddHHmmsss", CultureInfo.InvariantCulture) + "_" + Metadata.Name!;
     }
 
-    public async Task Perform(IServiceProvider? serviceProvider, IStartupLogger logger, CancellationToken cancellationToken)
+    public async Task Perform(IServiceProvider serviceProvider, IStartupLogger logger, CancellationToken cancellationToken)
     {
         if (!IsMigrationRoutine(MigrationType))
         {
             throw new InvalidOperationException($"The type {MigrationType} does not implement either IMigrationRoutine or IAsyncMigrationRoutine and is not a valid migration type");
         }
 
-        if (serviceProvider is null)
-        {
-            await RunAsync(Activator.CreateInstance(MigrationType)!, cancellationToken).ConfigureAwait(false);
-            return;
-        }
-
         // The routine runs against a scope of the applications own container. Copying the application service
         // descriptors into a child container instead would make that child container the owner of every singleton it
         // forwards, so disposing it after the migration would also dispose the applications own instance of services