fix(lab): prevent tasks linking to themselves

[eatyourgreens]

A second go at fixing this, previously fixed in #5925. Pass the current task key as a prop to NextTaskSelector. Filter the list of tasks to exclude that task key, so that a task can't link back to itself.

This has to be edited in the editors for each individual task type, but I think I got them all.

• Fixes Prevent the project builder from making a recursive decision tree if they add in a new question before the previous one entered into the workflow #2512 (for the second time.)

Required Manual Testing

• Does the non-logged in home page render correctly?
• Does the logged in home page render correctly?
• Does the projects page render correctly?
• Can you load project home pages?
• Can you load the classification page?
• Can you submit a classification?
• Does talk load correctly?
• Can you post a talk comment?

Review Checklist

• Does it work in all major browsers: Firefox, Chrome, Edge, Safari?
• Does it work on mobile?
• Can you npm ci and app works as expected?
• If the component is in coffeescript, is it converted to ES6? Is it free of eslint errors? Is the conversion its own commit?
• Are the tests passing locally and on GitHub Actions?

Optional

• Have you replaced any ChangeListener or PromiseRenderer components with code that updates component state?
• If changes are made to the classifier, does the dev classifier still work?
• Have you resized and compressed any image you've added?
• Have you added in flow type annotations?
• Have you followed the Springer guidelines for commit messages?

[coveralls]

coverage: 56.656% (-0.03%) from 56.684%
when pulling 8448bd9 on eatyourgreens:fix-next-task-selector
into 8ad3b19 on zooniverse:master.