docs: update currently supported versions for 7.0.0 release (#20622)

* [WIP] docs: update currently supported versions for 7.0.0 release

* oops

docs/tutorial/support.md

@@ -48,9 +48,9 @@ basis for some older supported lines. All contested decisions around release
 line backports will be resolved by the [Releases Working Group](https://github.com/electron/governance/tree/master/wg-releases) as an agenda item at their weekly meeting the week the backport PR is raised.
 
 ### Currently supported versions
+- 7.x.y
 - 6.x.y
 - 5.x.y
-- 4.x.y
 
 ### End-of-life