feat: update syntax for failing test to be more consistent

crates/aiken-lang/src/tests/format.rs

@@ -507,12 +507,12 @@ fn test_format_match_record() {
 fn test_format_fail() {
     assert_format!(
         r#"
-      !test foo() {
-        expect Some(a) = bar
+        test foo() fail {
+          expect Some(a) = bar
 
-        a
-      }
-    "#
+          a
+        }
+        "#
     );
 }
 

crates/aiken-lang/src/tests/snapshots/format_fail.snap

@@ -1,8 +1,8 @@
 ---
 source: crates/aiken-lang/src/tests/format.rs
-description: "Code:\n\n!test foo() {\n  expect Some(a) = bar\n\n  a\n}\n"
+description: "Code:\n\ntest foo() fail {\n  expect Some(a) = bar\n\n  a\n}\n"
 ---
-!test foo() {
+test foo() fail {
   expect Some(a) = bar
 
   a