Fix Talk tag search results to omit tag linked to deleted subject

[mcbouslog]

Staging branch URL: https://pr-7037.pfe-preview.zooniverse.org

Fixes issue documented in this contact ticket.

• bug: https://www.zooniverse.org/projects/zooniverse/gravity-spy/talk/tags/esdoverflow
• fix local: https://local.zooniverse.org:3735/projects/zooniverse/gravity-spy/talk/tags/esdoverflow?env=production
• fix preview: https://pr-7037.pfe-preview.zooniverse.org/projects/zooniverse/gravity-spy/talk/tags/esdoverflow

Describe your changes.

• adds conditional to check if subjects exists before updating tag with subject
• adds catch for subject request
• filters tags, removing tag if falsey or if tag.subject falsey

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: 56.965% (+0.003%) from 56.962% when pulling 728a3912f3bcf1b14c361cb95050a5b962b74968 on fix-talk-results into d9e2831236bb93429cdfcecd72410c5f9af760dd on master.

[shaunanoordin]

I'm tagging in (ha!) to review, one sec.