This has multiple advantages:

• It's tool agnostic (e.g. if we were to drop the ninja symlink for samu, we wouldn't have to change anything here)
• It allows for more fine grained control, e.g. in meson test, where we can increase timeouts and print the test log to stdout, something which we can't control when invoking it via ninja.

This is similiar to dd24cdf8, but for meson.