[interop][benchmark] disable CxxVectorSum benchmarks for now until SwiftPM build issue is resolved

Author: hyp

benchmark/cxx-source/CxxVectorSum.swift

@@ -14,6 +14,10 @@
 // as compared to the C++ implementation of such sum.
 
 import TestsUtils
+
+public let benchmarks: [BenchmarkInfo] = []
+#if FIX_61472
+
 import std
 
 // FIXME: remove workaround for: https://github.com/apple/swift/issues/61472
@@ -135,3 +139,4 @@ extension VectorOfU32.const_iterator : Equatable, UnsafeCxxInputIterator { }
 
 extension VectorOfU32: CxxSequence {}
 #endif
+#endif