Include args.gn file (to detect if -stdlib=libc++ was used to compile Skia)

Author: dacap

.github/workflows/build.yml

@@ -91,6 +91,7 @@ jobs:
         export dst=Skia-${{ runner.os }}-${{ matrix.mode }}-${{ matrix.arch }}
         mkdir $dst
         $cp -R --parents \
+          out/${{ matrix.mode }}-${{ matrix.arch }}/args.gn \
           out/${{ matrix.mode }}-${{ matrix.arch }}/*.$libext \
           include \
           modules/particles/include/*.h \