Update Backstage maintainers + add back Tremor

Signed-off-by: Patrik Oldsberg <[email protected]>

Author: Rugvip

project-maintainers.csv

@@ -868,14 +868,11 @@ Sandbox,k3s,Brad Davidson,SUSE,brandond,https://github.com/rancher/k3s/blob/mast
 ,,Robert Sirchia,SUSE,Robersirc,
 Incubating,Backstage,Patrik Oldsberg,Spotify,Rugvip,https://github.com/spotify/backstage/blob/master/OWNERS.md
 ,,Fredrik Adelöw,Spotify,freben,
-,,Johan Haals,Spotify,jhaals,
 ,,Ben Lambert,Spotify,benjdlambert,
 ,,Niklas Gustavsson,Spotify,protocol7,
 ,,Dave Zolotusky,Spotify,dzolotusky,
-,,Lee Mills,Spotify,leemills83,
-,,Himanshu Mishra,Spotify,orkohunter,
-,,Tim Hansen,Spotify,timbonicus,
-,,Darach Ennis,Axiom,darach,
+,,Pia Nilsson,Spotify,pianilsson,
+Sandbox,Tremor,Darach Ennis,Axiom,darach,
 ,,Heinz N. Gies,Axiom,Licenser,
 ,,Matthias Wahl,GSMK GmbH,mfelsche,
 ,,Natali Vlatko,Cisco,natalisucks,