retire inactive rdg member

Author: tshepang

teams/wg-rustc-dev-guide.toml

@@ -8,7 +8,6 @@ members = [
     "BoxyUwU",
     "JohnTitor",
     "camelid",
-    "igaray",
     "jieyouxu",
     "jyn514",
     "spastorino",
@@ -19,6 +18,7 @@ alumni = [
     "Nashenas88",
     "amanjeev",
     "chrissimpkins",
+    "igaray",
     "mark-i-m",
     "pierwill",
     "rylev",