Use JSValue instead for JSPromise's closure return types

Returning `some ConvertibleToJSValue` was not consistent with
`JSClosure` initializers, which always return `JSValue`. Also it emits
`Capture of non-sendable type '(some ConvertibleToJSValue).Type' in an
isolated closure` for some reasons.

Author: kateinoigakukun

Sources/JavaScriptKit/BasicObjects/JSPromise.swift

@@ -98,7 +98,7 @@ public final class JSPromise: JSBridgedClass {
     @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
     @discardableResult
     public func then(
-        success: sending @escaping (sending JSValue) async throws -> some ConvertibleToJSValue
+        success: sending @escaping (sending JSValue) async throws -> JSValue
     ) -> JSPromise {
         let closure = JSOneshotClosure.async {
             try await success($0[0]).jsValue
@@ -127,8 +127,8 @@ public final class JSPromise: JSBridgedClass {
     @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
     @discardableResult
     public func then(
-        success: sending @escaping (sending JSValue) async throws -> some ConvertibleToJSValue,
-        failure: sending @escaping (sending JSValue) async throws -> some ConvertibleToJSValue
+        success: sending @escaping (sending JSValue) async throws -> JSValue,
+        failure: sending @escaping (sending JSValue) async throws -> JSValue
     ) -> JSPromise {
         let successClosure = JSOneshotClosure.async {
             try await success($0[0]).jsValue
@@ -158,7 +158,7 @@ public final class JSPromise: JSBridgedClass {
     @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
     @discardableResult
     public func `catch`(
-        failure: sending @escaping (sending JSValue) async throws -> some ConvertibleToJSValue
+        failure: sending @escaping (sending JSValue) async throws -> JSValue
     ) -> JSPromise {
         let closure = JSOneshotClosure.async {
             try await failure($0[0]).jsValue