tests: switch to std::filesystem

Change-Id: I4c8df25b83c36debb4d70f6c7757545ae881e332
diff --git a/.waf-tools/default-compiler-flags.py b/.waf-tools/default-compiler-flags.py
index 3e001a9..3c724fe 100644
--- a/.waf-tools/default-compiler-flags.py
+++ b/.waf-tools/default-compiler-flags.py
@@ -136,7 +136,7 @@
         return {
             'CXXFLAGS': [],
             'LINKFLAGS': [],
-            'DEFINES': ['BOOST_ASIO_NO_DEPRECATED', 'BOOST_FILESYSTEM_NO_DEPRECATED'],
+            'DEFINES': ['BOOST_ASIO_NO_DEPRECATED'],
         }
 
     def getOptimizedFlags(self, conf):