Add Diego Russo as code owner of the JIT (python#136460)

Author: diegorusso

.github/CODEOWNERS

@@ -26,7 +26,7 @@ Modules/Setup*                @erlend-aasland
 **/*context*                  @1st1
 **/*genobject*                @markshannon
 **/*hamt*                     @1st1
-**/*jit*                      @brandtbucher @savannahostrowski
+**/*jit*                      @brandtbucher @savannahostrowski @diegorusso
 Objects/set*                  @rhettinger
 Objects/dict*                 @methane @markshannon
 Objects/typevarobject.c       @JelleZijlstra