Similar to https://github.com/mongodb/mongo/blob/master/distsrc/THIRD-PARTY-NOTICES

It should include the headers from the following files:

bson/bson-stdint-win32.h (3 clause BSD License)
bson/encoding_helpers.c (Unicode, Inc.)
bson/time64.c (MIT License)
pymongo/ssl_match_hostname.py (Python Software Foundation License Version 2)