Prevent doing layer collection resync during most of `blo_read_file_internal` process. This is dangerous (since during blendfile read there is no way to ensure that Main is in a fully valid sate), and a useless costly process.
Prevent doing layer collection resync during most of `blo_read_file_internal` process. This is dangerous (since during blendfile read there is no way to ensure that Main is in a fully valid sate), and a useless costly process.