Move spastorino to Rustc Dev Guide Alumni

Author: spastorino

teams/wg-rustc-dev-guide.toml

@@ -10,7 +10,6 @@ members = [
     "camelid",
     "jieyouxu",
     "jyn514",
-    "spastorino",
     "tshepang",
 ]
 alumni = [
@@ -22,6 +21,7 @@ alumni = [
     "mark-i-m",
     "pierwill",
     "rylev",
+    "spastorino",
     "togiberlin",
 ]