[Fix] Bookmark column to support null

[esizer]

🤖 Resolves #8977

👋 Introduction

Without a default value/nullable the bookmark column was causing issues for existing rows. This updates the migration to make it nullable with null as a default value. As well, it makes the field optional in the factory so we can simulate this locally as well.

🕵️ Details

I wasn't sure if we had already ran this migration but the AC mentioned updating the migration instead of creating a new one. If we have and it would be safer to create a new migration, let me know and I can fix that.

🧪 Testing

  mutation ToggleBookmark_Mutation($id: ID!) {
    togglePoolCandidateBookmark(id: $id)
  }

1. Run migrations docker-compose exec -w /home/site/wwwroot/api webserver sh -c "php artisan migrate"
2. Navigate to /graphiql
3. Attempt to bookmark a candidate
4. Confirm there is no error
5. Confirm the new value is in the database
6. Seed new data docker-compose exec -w /home/site/wwwroot/api webserver sh -c "php artisan migrate:fresh --seed"
7. Confirm there are a mix of null, true, false bookmarked candidates
8. Toggle the bookmark on a candidate with null from null to true from the grappql mutation
9. Confirm it works as expected
10. Repeat steps 8-9 between true and false

[petertgiles]

Great!

[petertgiles]

I added an explicit deployment note and release to the issue.