docs: note that find_program accepts file objects
docs: note that find_program accepts file objects

This was implemented in commit 280346da3ac5904ec097afe89ef45ad34bd4a173
but never properly documented (it predated the version-controlled docs).

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