Testing module is not included in 6.0 SDK

Author: kateinoigakukun

Plugins/PackageToJS/Tests/ExampleTests.swift

@@ -289,6 +289,7 @@ extension Trait where Self == ConditionTrait {
         }
     }
 
+    #if compiler(>=6.1)
     // TODO: Remove triple restriction once swift-testing is shipped in p1-threads SDK
     @Test(.requireSwiftSDK(triple: "wasm32-unknown-wasi"))
     func continuationLeakInTest_SwiftTesting() throws {
@@ -300,4 +301,5 @@ extension Trait where Self == ConditionTrait {
             try runSwift(["package", "--disable-sandbox", "--swift-sdk", swiftSDKID, "js", "test"], [:])
         }
     }
+    #endif
 }