compilers/compilers: Fix some potential issues spotted by pyright
compilers/compilers: Fix some potential issues spotted by pyright

There are two changes here, one is to remove an `elif` that is
effectively an `else`, that helps the type checker and provides a small
speedup potentially. The second is a potentially unbound variable, that
currently isn't hit, but very much could be.

mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,mesonbuild/meson,pexip/meson,pexip/meson,pexip/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,pexip/meson,pexip/meson,pexip/meson,mesonbuild/meson,pexip/meson,pexip/meson,mesonbuild/meson