ast/introspection: Fix typing violation due to untyped functions
ast/introspection: Fix typing violation due to untyped functions

When we add type annotations to this in compilers this will break,
unless we've already filtered out the non-string arguments.

pexip/meson,pexip/meson,jpakkane/meson,mesonbuild/meson,mesonbuild/meson,QuLogic/meson,pexip/meson,jpakkane/meson,mesonbuild/meson,jpakkane/meson,pexip/meson,mesonbuild/meson,QuLogic/meson,pexip/meson,pexip/meson,pexip/meson,QuLogic/meson,pexip/meson,QuLogic/meson,pexip/meson,mesonbuild/meson,mesonbuild/meson,jpakkane/meson,mesonbuild/meson,mesonbuild/meson,QuLogic/meson,jpakkane/meson,QuLogic/meson,pexip/meson,QuLogic/meson,jpakkane/meson,jpakkane/meson,QuLogic/meson,mesonbuild/meson,QuLogic/meson,jpakkane/meson,mesonbuild/meson,jpakkane/meson