Use non-captured identifier in format string

To ensure that MSRV of 1.56.1 still holds, replace the captured
identifier in format strings. Capturing identifierts for format strings
was introduced with Rust 1.58.0.

rustler_tests/native/rustler_test/src/test_tuple.rs

@@ -34,8 +34,11 @@ pub fn greeting_person_from_tuple(age_and_name: (u8, &str)) -> String {
     let (age, name) = age_and_name;
 
     if age > 18 {
-        format!("Hello, {name}! You are allowed in the bar area.")
+        format!("Hello, {}! You are allowed in the bar area.", name)
     } else {
-        format!("Hi, {name}! I'm sorry, but you are not allowed in the bar area.")
+        format!(
+            "Hi, {}! I'm sorry, but you are not allowed in the bar area.",
+            name
+        )
     }
 }