This will reduce the likelihood of them navigating away to another page of the site and abandoning their cart.
Keep minimal links in the footer, such as your FAQ, shipping & return policies, and contact info.
To be clear, I don’t mean not allowing people from navigating back (with links, or worst case, simply with the back button to go back) to the cart then keep shopping. For a good example to illustrate this best practice, take a look at how Shopify does it (see below). The header and footer are removed, but they keep a couple of ways to go back to the cart / bag (the breadcrumbs and a back link, highlighted in red).
That way, it focuses the shopper on the checkout and avoids distractions, while still allowing them to keep shopping if they’re not ready to buy.
This is actually a common and best practice.