Remove @varkor from compiler-team

I've stepped down from the compiler team, and I don't have time to review at the moment. I hope to be added back to review rotation as soon as my workload has decreased.

Author: varkor

highfive/configs/rust-lang/rust.json

@@ -5,7 +5,6 @@
             "@estebank",
             "@matthewjasper",
             "@petrochenkov",
-            "@varkor",
             "@davidtwco",
             "@oli-obk",
             "@nagisa"