I tested this locally and the email threads are rendering correctly.
Why
We need to upgrade d3-colour to 3.1.0 due to vulnerability https://github.com/guardian/giant/security/dependabot/2
But d3 library depends on d3-colour and to be able to update d3-colour we had to upgrade d3 from v4 to v7.
What does this change?
This PR upgrades d3 library. The only usage of this library is in https://github.com/guardian/giant/blob/main/frontend/src/js/components/EmailBrowser/Timeline.js#L5
I tested this locally and the email threads are rendering correctly.
Why
We need to upgrade d3-colour to 3.1.0 due to vulnerability https://github.com/guardian/giant/security/dependabot/2 But d3 library depends on d3-colour and to be able to update d3-colour we had to upgrade d3 from v4 to v7.