Upgrade JsonMapper to 4.1.0

Summary:
This version upgrade allows to avoid the following issue:

[21-Dec-2022 18:56:04 UTC] PHP Fatal error:
Array and string offset access syntax with curly braces is no longer supported
in /srv/api/servers-log/vendor/netresearch/jsonmapper/src/JsonMapper.php on line 300

Fixes T1737.

Test Plan: Run tests, fire log entry

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1737

Differential Revision: https://devcentral.nasqueron.org/D2724