Update d3 from version 5.9.2 to 6.7.0
Summary:
Update the d3 library to its last 6.x version available on https://github.com/d3/d3/releases
This also requires updating the tooltip event handling of dots in `Chart.js` to avoid an `Uncaught TypeError: d3.event is undefined` per https://observablehq.com/@d3/d3v6-migration-guide#event-management linked from https://github.com/d3/d3/releases/tag/v6.0.0
Closes T15820
Test Plan:
* Enable the Facts application, go to the Reports of a Project with task changes over time, look at charts, hover over data points, read the tooltip - e.g. on http://phorge.localhost/project/reports/1/ or http://phorge.localhost/maniphest/report/burn/
* Check HTML source of above URIs for the `<script type="text/javascript">` loading `d3.min.js` and open the JS file to verify the d3 version number bump.
* Check Console of web browser's developer tools for no errors.
Reviewers: O1 Blessed Committers, speck
Reviewed By: O1 Blessed Committers, speck
Subscribers: speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T15820
Differential Revision: https://we.phorge.it/D25631