fix(cmake): avoid really slow compile on emscripten (#4642)

* fix: avoid really slow compile on emscripten

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Update tools/pybind11Common.cmake

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
1 file changed