Remove TODO comment that cannot be done

After finishing work on HPC-9121, ticket HPC-9637
was opened to track how we can set column `latestVersionId`
in `project` table to be `NOT NULL`. But, turns
out that will not be possible, so we need this check,
cannot remove it, as TODO desired.

src/db/deletion/project.ts

@@ -22,7 +22,7 @@ export const deleteProjectById = async (
 
   // Cannot delete already published project
   if (
-    project.latestVersionId !== null && // TODO: Remove once HPC-9121 is done and `latestVersionId` can no longer be `null`
+    project.latestVersionId !== null &&
     project.currentPublishedVersionId === project.latestVersionId
   ) {
     throw new PreconditionFailedError(