Concurrency: Use LazyThreadLocal without @pw syntax

Unfortunately, `@LazyThreadLocal static var` is considered as
concurrency-unsafe in Swift 6 mode even though the underlying PW storage
is read-only and concurrency-safe. Also Swift bans `static let` with
`@propertyWrapper` syntax, so we need to use `LazyThreadLocal` directly.

See the discussion in the Swift forum:
https://forums.swift.org/t/static-property-wrappers-and-strict-concurrency-in-5-10/70116/27

Author: kateinoigakukun

Sources/JavaScriptKit/BasicObjects/JSArray.swift

@@ -2,9 +2,8 @@
 /// class](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)
 /// that exposes its properties in a type-safe and Swifty way.
 public class JSArray: JSBridgedClass {
-    public static var constructor: JSFunction? { _constructor }
-    @LazyThreadLocal(initialize: { JSObject.global.Array.function })
-    private static var _constructor: JSFunction?
+    public static var constructor: JSFunction? { _constructor.wrappedValue }
+    private static let _constructor = LazyThreadLocal(initialize: { JSObject.global.Array.function })
 
     static func isArray(_ object: JSObject) -> Bool {
         constructor!.isArray!(object).boolean!

Sources/JavaScriptKit/BasicObjects/JSDate.swift

@@ -8,9 +8,8 @@
  */
 public final class JSDate: JSBridgedClass {
     /// The constructor function used to create new `Date` objects.
-    public static var constructor: JSFunction? { _constructor }
-    @LazyThreadLocal(initialize: { JSObject.global.Date.function })
-    private static var _constructor: JSFunction?
+    public static var constructor: JSFunction? { _constructor.wrappedValue }
+    private static let _constructor = LazyThreadLocal(initialize: { JSObject.global.Date.function })
 
     /// The underlying JavaScript `Date` object.
     public let jsObject: JSObject

Sources/JavaScriptKit/BasicObjects/JSError.swift

@@ -4,9 +4,8 @@
  */
 public final class JSError: Error, JSBridgedClass {
     /// The constructor function used to create new JavaScript `Error` objects.
-    public static var constructor: JSFunction? { _constructor }
-    @LazyThreadLocal(initialize: { JSObject.global.Error.function })
-    private static var _constructor: JSFunction?
+    public static var constructor: JSFunction? { _constructor.wrappedValue }
+    private static let _constructor = LazyThreadLocal(initialize: { JSObject.global.Error.function })
 
     /// The underlying JavaScript `Error` object.
     public let jsObject: JSObject

Sources/JavaScriptKit/BasicObjects/JSTypedArray.swift

@@ -143,19 +143,17 @@ func valueForBitWidth<T>(typeName: String, bitWidth: Int, when32: T) -> T {
 }
 
 extension Int: TypedArrayElement {
-    public static var typedArrayClass: JSFunction { _typedArrayClass }
-    @LazyThreadLocal(initialize: {
+    public static var typedArrayClass: JSFunction { _typedArrayClass.wrappedValue }
+    private static let _typedArrayClass = LazyThreadLocal(initialize: {
         valueForBitWidth(typeName: "Int", bitWidth: Int.bitWidth, when32: JSObject.global.Int32Array).function!
     })
-    private static var _typedArrayClass: JSFunction
 }
 
 extension UInt: TypedArrayElement {
-    public static var typedArrayClass: JSFunction { _typedArrayClass }
-    @LazyThreadLocal(initialize: {
+    public static var typedArrayClass: JSFunction { _typedArrayClass.wrappedValue }
+    private static let _typedArrayClass = LazyThreadLocal(initialize: {
         valueForBitWidth(typeName: "UInt", bitWidth: Int.bitWidth, when32: JSObject.global.Uint32Array).function!
     })
-    private static var _typedArrayClass: JSFunction
 }
 
 extension Int8: TypedArrayElement {

Sources/JavaScriptKit/FundamentalObjects/JSObject.swift

@@ -24,9 +24,8 @@ import _CJavaScriptKit
 /// reference counting system.
 @dynamicMemberLookup
 public class JSObject: Equatable {
-    internal static var constructor: JSFunction { _constructor }
-    @LazyThreadLocal(initialize: { JSObject.global.Object.function! })
-    internal static var _constructor: JSFunction
+    internal static var constructor: JSFunction { _constructor.wrappedValue }
+    private static let _constructor = LazyThreadLocal(initialize: { JSObject.global.Object.function! })
 
     @_spi(JSObject_id)
     public var id: JavaScriptObjectRef
@@ -206,12 +205,10 @@ public class JSObject: Equatable {
 
     /// A `JSObject` of the global scope object.
     /// This allows access to the global properties and global names by accessing the `JSObject` returned.
-    public static var global: JSObject { return _global }
-
-    @LazyThreadLocal(initialize: {
-        return JSObject(id: _JS_Predef_Value_Global)
+    public static var global: JSObject { return _global.wrappedValue }
+    private static let _global = LazyThreadLocal(initialize: {
+        JSObject(id: _JS_Predef_Value_Global)
     })
-    private static var _global: JSObject
 
     deinit {
         assertOnOwnerThread(hint: "deinitializing")