libbson 1.28.1

Fixes:

• Fix large string handling in bson_string_truncate.
• Fix possible crash in bson_value_copy.

libmongoc 1.28.1

Fixes:

• Do not return result in mongoc_bulkwritereturn_t if there are no known successful writes.
• Validate lengths in ill-formed server responses.
• Do not override read preference when using aggregate with $out/$merge with unscanned servers.
• Remove unexpected warning if authSource in TXT record is overriden by URI option.
• Fix crash when non-existent CA file configured with OpenSSL.