Update crates/aiken-lang/src/parser.rs

Co-authored-by: Matthias Benkort <5680256+KtorZ@users.noreply.github.com>

crates/aiken-lang/src/parser.rs

@@ -305,9 +305,9 @@ pub fn validator_parser() -> impl Parser<Token, ast::UntypedDefinition, Error =
 
             ast::UntypedDefinition::Validator(ast::Validator {
                 doc: None,
-                // unwrap is safe to do here because
-                // above we use `.at_least(1)`
-                fun: functions.next().unwrap(),
+                fun: functions
+                  .next()
+                  .expect("unwrapping safe because there's 'at_least(1)' function"),
                 other_fun: functions.next(),
                 location: Span {
                     start: span.start,