Add a CI check for todo! and FIXME comments (#21950)

Motivation for this is to support writing comments that will certainly
be revisited before merge.

Release Notes:

- N/A

crates/repl/src/notebook/notebook_ui.rs

@@ -515,7 +515,7 @@ impl project::ProjectItem for NotebookItem {
                     Ok(nbformat::Notebook::V4(notebook)) => notebook,
                     // 4.1 - 4.4 are converted to 4.5
                     Ok(nbformat::Notebook::Legacy(legacy_notebook)) => {
-                        // todo!(): Decide if we want to mutate the notebook by including Cell IDs
+                        // TODO: Decide if we want to mutate the notebook by including Cell IDs
                         // and any other conversions
                         let notebook = nbformat::upgrade_legacy_notebook(legacy_notebook)?;
                         notebook