Fix Swift 6.2 compile issue around ExecutorFactory API

The `ExecutorFactory` API was reverted in Swift 6.2, so we have to
change the guard to Swift 6.3.

Author: kateinoigakukun

Sources/JavaScriptEventLoop/JavaScriptEventLoop+ExecutorFactory.swift

@@ -7,7 +7,7 @@
 import _Concurrency
 import _CJavaScriptKit
 
-#if compiler(>=6.2)
+#if compiler(>=6.3)
 
 // MARK: - MainExecutor Implementation
 // MainExecutor is used by the main actor to execute tasks on the main thread
@@ -104,4 +104,4 @@ extension JavaScriptEventLoop: ExecutorFactory {
     }
 }
 
-#endif  // compiler(>=6.2)
+#endif  // compiler(>=6.3)

Sources/JavaScriptEventLoop/JavaScriptEventLoop.swift

@@ -119,9 +119,9 @@ public final class JavaScriptEventLoop: SerialExecutor, @unchecked Sendable {
     private static func installGlobalExecutorIsolated() {
         guard !didInstallGlobalExecutor else { return }
         didInstallGlobalExecutor = true
-        #if compiler(>=6.2)
+        #if compiler(>=6.3)
         if #available(macOS 9999, iOS 9999, watchOS 9999, tvOS 9999, visionOS 9999, *) {
-            // For Swift 6.2 and above, we can use the new `ExecutorFactory` API
+            // For Swift 6.3 and above, we can use the new `ExecutorFactory` API
             _Concurrency._createExecutors(factory: JavaScriptEventLoop.self)
         }
         #else