Add in new full-TSC members

Following the provisional period, welcome to the new maintainers! Thank you for all the work you've put in until now and for the progress yet to come. 🙏

MAINTAINERS.md

@@ -5,8 +5,6 @@
 * Jeremy Whitlock [@whitlockjc](https://github.com/whitlockjc)
 * Marsh Gardiner [@earth2marsh](https://github.com/earth2marsh)
 * Ron Ratovsky [@webron](https://github.com/webron)
-
-## Provisional
 * Lorna Mitchell [@lornajane](https://github.com/lornajane)
 * Mike Kistler [@mikekistler](https://github.com/mikekistler)
 * Miguel Quintero [@miqui](https://github.com/miqui)