dotnet: strip native symbols from runtime

This reduces the output size of dotnet_9.vmr from 4.2GiB to 1.9GiB.

pkgs/development/compilers/dotnet/vmr.nix

@@ -187,6 +187,14 @@ in stdenv.mkDerivation rec {
     substituteInPlace \
       src/runtime/src/native/libs/CMakeLists.txt \
       --replace-fail 'add_compile_options(-Weverything)' 'add_compile_options(-Wall)'
+
+    # strip native symbols in runtime
+    # see: https://github.com/dotnet/source-build/issues/2543
+    xmlstarlet ed \
+      --inplace \
+      -s //Project -t elem -n PropertyGroup \
+      -s \$prev -t elem -n KeepNativeSymbols -v false \
+      src/runtime/Directory.Build.props
   ''
   + lib.optionalString isLinux ''
     substituteInPlace \