build: Remove NS3_ENABLE_EXAMPLES flag

examples_as_tests_dependencies macro adds examples called by tests as CMake target dependencies

build-support/custom-modules/ns3-module-macros.cmake

@@ -183,10 +183,6 @@ function(build_lib)
     target_precompile_headers(${BLIB_LIBNAME} REUSE_FROM stdlib_pch)
   endif()
 
-  if(${ENABLE_EXAMPLES} AND ${ENABLE_TESTS})
-    target_compile_definitions(${BLIB_LIBNAME} PRIVATE NS3_ENABLE_EXAMPLES)
-  endif()
-
   # Associate public headers with library for installation purposes
   set_target_properties(
     ${BLIB_LIBNAME}

src/core/model/example-as-test.cc

@@ -42,7 +42,6 @@ namespace ns3
 NS_LOG_COMPONENT_DEFINE("ExampleAsTestCase");
 
 // Running tests as examples currently requires Python.
-#if defined(NS3_ENABLE_EXAMPLES)
 
 ExampleAsTestCase::ExampleAsTestCase(const std::string name,
                                      const std::string program,
@@ -161,6 +160,4 @@ ExampleAsTestSuite::ExampleAsTestSuite(const std::string name,
     AddTestCase(new ExampleAsTestCase(name, program, dataDir, args, shouldNotErr), duration);
 }
 
-#endif // NS3_ENABLE_EXAMPLES
-
 } // namespace ns3