Support mold linker

[sjunges]

Hi,

while waiting for Storm to link on linux... I found this

https://www.productive-cpp.com/using-the-mold-linker-for-fun-and-3x-8x-link-time-speedups/

I believe this could be a tremendous step towards faster CI.

Sebastian

[volkm]

I tried building with mold, see this branch and this action. Some first insights:

• mold is available as package for Ubuntu >= 22.04 and Debian >= 12.
• Older versions of mold do not support LTO and fall back to ld
• comparing timings with mold and without there seems to be a small improvement. But as the CI time can vary quite a bit, more experiments would be needed.

[sjunges]

Cool!

Thanks for looking into it this quickly. Indeed, the difference seems not big as the mold website indicates. :(