component/theia: support compilation on device with 2GB RAM

Without this commit, compilation fails with:

Reached heap limit Allocation failed - JavaScript heap out of memory

See merge request nexedi/slapos!1317

component/theia/buildout.cfg

@@ -38,6 +38,7 @@ environment =
   PATH=${nodejs:location}/bin:${pkgconfig:location}/bin:${python3:location}/bin:%(PATH)s
   PKG_CONFIG_PATH=${libsecret:pkg-config-path}
   LDFLAGS=-Wl,-rpath=${libsecret:location}/lib -L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib -Wl,-rpath=${glib:location}/lib
+  NODE_OPTIONS=--max_old_space_size=4096
 pre-configure =
   mkdir -p $TMPDIR
   echo '${package.json:content}' > %(location)s/package.json