Use the new more efficient .NET 9 Lock type (#18015)

src/Umbraco.Core/Composing/CollectionBuilderBase.cs

@@ -13,7 +13,7 @@ public abstract class CollectionBuilderBase<TBuilder, TCollection, TItem> : ICol
     where TBuilder : CollectionBuilderBase<TBuilder, TCollection, TItem>
     where TCollection : class, IBuilderCollection<TItem>
 {
-    private readonly object _locker = new();
+    private readonly Lock _locker = new();
     private readonly List<Type> _types = new();
     private Type[]? _registeredTypes;
 

src/Umbraco.Core/Composing/TypeFinder.cs

@@ -40,7 +40,7 @@ public class TypeFinder : ITypeFinder
     private static readonly ConcurrentDictionary<string, Type?> TypeNamesCache = new();
 
     private readonly IAssemblyProvider _assemblyProvider;
-    private readonly object _localFilteredAssemblyCacheLocker = new();
+    private readonly Lock _localFilteredAssemblyCacheLocker = new();
     private readonly ILogger<TypeFinder> _logger;
     private readonly List<string> _notifiedLoadExceptionAssemblies = new();
 

src/Umbraco.Core/Composing/TypeLoader.cs

@@ -20,7 +20,7 @@ namespace Umbraco.Cms.Core.Composing;
 /// </remarks>
 public sealed class TypeLoader
 {
-    private readonly object _locko = new();
+    private readonly Lock _locko = new();
     private readonly ILogger<TypeLoader> _logger;
 
     private readonly Dictionary<CompositeTypeTypeKey, TypeList> _types = new();