Hide all mentions/links to User Panel and Roadmap

[jennpb]

What?

Hide all mentions and links to the user panel and roadmap Delist the Join the user panel page so it can be republished later

Todo

• [x] Remove <div> from Concepts header We’re working to improve the information on this page. You can [join our user panel](https://wellcomecollection.org/user-panel) or [submit an idea](https://roadmap.wellcomecollection.org/) that would help you use our website. https://wellcomecollection.org/concepts/fd5f4p45
• [x] Delist Join the user panel page in Prismic (jenn can do this)
• [x] Remove user panel card from Get involved

Why?

We are pausing the user panel until there is dedicated User Research capacity for Wellcome Collection. We don't want to continue to collect personal information we're not using.

The public roadmap (based in Productboard) has been shut off until future PMs decide if they want to use it.

[georgiaewhitney]

https://github.com/wellcomecollection/wellcomecollection.org/pull/10167 - fixes first tickbox

[georgiaewhitney]

Now in prod 👍