Bless tests

Update tests

tests/rustdoc-ui/feature-gate-custom_code_classes_in_docs.rs

@@ -6,6 +6,7 @@
 //~^^^ WARNING custom classes in code blocks will change behaviour
 //~| NOTE found these custom classes: class=language-c
 //~| NOTE see issue #79483 <https://github.com/rust-lang/rust/issues/79483>
+//~| NOTE: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 //~| HELP add `#![feature(custom_code_classes_in_docs)]` to the crate attributes to enable
 pub struct Bar;