.github/workflows/d.yml:add macos test

[andy5995]

(related to #23)

[andy5995]

Test shows as passed, but the build output shows errors (exited with 1).

I don't know how to fix it though; though it may be possible if you remove the -static flag, it may work.

Some extra info here

https://stackoverflow.com/questions/3801011/ld-library-not-found-for-lcrt0-o-on-osx-10-6-with-gcc-clang-static-flag

[andy5995]

MacOS Tests and build seems to be working now.

I'll remove the commented lines if you want to use this as-is...

[rushsteve1]

I think it might be defaulting to compiling with DMD, which means that the end binary is not statically linked and relies on the Phobos shared library. This is less than ideal, it makes installing on MacOS that much harder.