Mission page should be statically generated

[bencodezen]

What needs fixed?

Missions page currently fetches all published missions on Sanity on each page load.

How do you propose it should be fixed?

We should move the logic for fetching into staticProps and out of contexts so that we don't fetch it on every load.

[philhawksworth]

Absolutely!

If we are hitting the content API at request time rather than build time we'll be breaking the atomic nature of builds, so this is really important to resolve. Good call out!