That's a 'maybe'.
First, the rear brake line is never too short because of how it is routed to the rear brakes. The front brake lines are only sometimes too short. With a very flexible high-end 4" lift, they could
be too short. With a typical 4" lift, not all that flexible in other words, they will probably be fine. I had a non-super flexible 5.5" RockKrawler lift on my TJ years ago and my stock brake lines were still fine. All I did was lower the front brake line frame mount for them 1" with the bracket extension I got, I think, with my old Tera Quick Disconnect kit for the front antiswaybar links (which makes the front suspension more flexible).
If you do end up needing slightly longer front brake lines, all you need are the factory brake lines for an older YJ (95 or older) Wrangler which are slightly longer than the TJ's brake lines. They are high quality and low in cost, and they are a direct bolt-in replacement. You don't need fancy stainless steel braid covered lines which doesn't really make them stronger anyway.