Merge pull request #68294 from compnerd/move-to-the-future

swift-plugin-server: default to C++17

Author: compnerd

tools/swift-plugin-server/Package.swift

@@ -34,6 +34,6 @@ let package = Package(
         "CSwiftPluginServer"
       ]
     ),
-    
-  ]
+  ],
+  cxxLanguageStandard: .cxx17
 )