Rechartering to maintenance mode

Dear RCH Working Group participants,

back in February, we decided to recharter into a maintenance WG 
<https://www.w3.org/2024/02/28-rch-minutes.html#x145>.

I have let this linger and I apologize. I just requested a small charter 
extension to allow us to finalize the actual rechartering...

We have a PR open on the previous charter with what would be the new 
charter:

https://github.com/w3c/rch-wg-charter/pull/110


Any comment/review is welcome. I don't think that we need a meeting to 
approve this (unless the chairs think otherwise and/or some 
controversial topic emerges in the discussion).

   best