test(sub): Ensure works on all platforms

crates/snapbox/src/substitutions.rs

@@ -536,7 +536,8 @@ mod test {
     fn substitute_disabled() {
         let input = "cargo";
         let pattern = "cargo[EXE]";
-        let sub = Substitutions::with_exe();
+        let mut sub = Substitutions::new();
+        sub.insert("[EXE]", "").unwrap();
         let actual = normalize(input, pattern, &sub);
         assert_eq!(actual, pattern);
     }