macOS nightly builds are missing gstreamer plugins

[jdm]

godot:MacOS jdm$ ./servo
Error initializing GStreamer: ErrorLoadingPlugins(["libgstapp.so", "libgstaudioconvert.so", "libgstaudiofx.so", "libgstaudioparsers.so", "libgstaudioresample.so", "libgstautodetect.so", "libgstcoreelements.so", "libgstdeinterlace.so", "libgstinterleave.so", "libgstisomp4.so", "libgstlibav.so", "libgstmatroska.so", "libgstogg.so", "libgstopengl.so", "libgstopus.so", "libgstplayback.so", "libgstproxy.so", "libgstrtp.so", "libgsttheora.so", "libgsttypefindfunctions.so", "libgstvideoconvert.so", "libgstvideofilter.so", "libgstvideoparsersbad.so", "libgstvideoscale.so", "libgstvorbis.so", "libgstvolume.so", "libgstvpx.so", "libgstwebrtc.so"])

[jdm]

Note to self: copy_dependencies in package_commands.py only includes the dylibs. Check if we need to do anything special to the .so files, or if we can just throw them in the set of files to be packaged.