osx: fix relocation of binaries without extension
osx: fix relocation of binaries without extension

The check by extension was only relocation libraries
and skipping binaries. This fix also looks for Mach-O files
if the extension check fails

Fixes: #285
Part-of: <https://gitlab.freedesktop.org/gstreamer/cerbero/-/merge_requests/565>

GStreamer/cerbero,GStreamer/cerbero,GStreamer/cerbero,GStreamer/cerbero,nirbheek/cerbero,nirbheek/cerbero,GStreamer/cerbero,nirbheek/cerbero,nirbheek/cerbero