Revert WasmKit special case in SwiftTestCommand.swift

After swiftlang/swift#80820 was merged this change is no longer needed.

Author: MaxDesiatov

Sources/Commands/SwiftTestCommand.swift

@@ -966,9 +966,6 @@ final class TestRunner {
             args.append(runnerPath.pathString)
             args.append(contentsOf: runner.extraCLIOptions)
             args.append(testPath.relative(to: localFileSystem.currentWorkingDirectory!).pathString)
-            if runner.path?.components.last == "wasmkit" {
-                args.append("--")
-            }
             args.append(contentsOf: self.additionalArguments)
         } else {
 #if os(macOS)