Always enable optimized Manifold

Found out the hard way that a Debug manifold build without optimization is MUCH
slower - impractically slow when it comes to things like plate mode bot
offsetting.

In the (rare) event we really need something like understandable perf reporting
on Linux, this setting can be manually turned off in this file.

manifold/CMakeLists.txt

@@ -23,6 +23,7 @@ if (ENABLE_MANIFOLD)
     -Dpugixml_ROOT=$<$<BOOL:${PUGIXML_TARGET}>:${CMAKE_BUNDLE_INSTALL_PREFIX}>
     -DMANIFOLD_TEST=OFF
     -DMANIFOLD_EXPORT=ON
+    -DMANIFOLD_OPTIMIZED=ON
     $<$<BOOL:${PUGIXML_TARGET}>:-DREQUIRE_EXT_PUGIXML=ON>
     -DGLM_BUILD_LIBRARY=OFF
     -DGLM_BUILD_INSTALL=ON