SIGSEGV github.com/jesseduffield/lazygit/pkg/commands/models.(*RemoteBranch).FullName(0xc0009afc20?)

In my terminal, i did `git checkout main && git pull --prune origin` on the repository that lazygit was open at in another terminal and it crashed. There were about 20 branches pruned in the pull, maybe this is what caused the problem ? Unsure how to correctly title this issue, feel free to change it.

```
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0x7fe4ae]

goroutine 473546 [running]:
github.com/jesseduffield/lazygit/pkg/commands/models.(*RemoteBranch).FullName(0xc0009afc20?)
/home/runner/work/lazygit/lazygit/pkg/commands/models/remote_branch.go:10 +0xe
github.com/jesseduffield/lazygit/pkg/gui/context.NewRemoteBranchesContext.func3.GetRemoteBranchListDisplayStrings.1(0x0, 0xc000c32740?)
/home/runner/work/lazygit/lazygit/pkg/gui/presentation/remote_branches.go:12 +0x2a
github.com/samber/lo.Map[...]({0xc000e35590?, 0x2, 0xe5c2a0}, 0xc0009afcb8?)
/home/runner/work/lazygit/lazygit/vendor/github.com/samber/lo/slice.go:29 +0x74
github.com/jesseduffield/lazygit/pkg/gui/presentation.GetRemoteBranchListDisplayStrings(...)
/home/runner/work/lazygit/lazygit/pkg/gui/presentation/remote_branches.go:11
github.com/jesseduffield/lazygit/pkg/gui/context.NewRemoteBranchesContext.func3(0x0?, 0x0?)
/home/runner/work/lazygit/lazygit/pkg/gui/context/remote_branches_context.go:32 +0xa5
github.com/jesseduffield/lazygit/pkg/gui/context.(*ListRenderer).renderLines(0xc0002a1790, 0xffffffffffffffff, 0xffffffffffffffff)
/home/runner/work/lazygit/lazygit/pkg/gui/context/list_renderer.go:88 +0x1b1
github.com/jesseduffield/lazygit/pkg/gui/context.(*ListContextTrait).HandleRender(0xc0002a1780)
/home/runner/work/lazygit/lazygit/pkg/gui/context/list_context_trait.go:96 +0x45
github.com/jesseduffield/lazygit/pkg/gui.(*Gui).postRefreshUpdate(0xc00029a608, {0xe627a8, 0xc000018408})
/home/runner/work/lazygit/lazygit/pkg/gui/view_helpers.go:140 +0xc7
github.com/jesseduffield/lazygit/pkg/gui.(*guiCommon).PostRefreshUpdate(0xc0008023d0?, {0xe627a8?, 0xc000018408?})
/home/runner/work/lazygit/lazygit/pkg/gui/gui_common.go:33 +0x25
github.com/jesseduffield/lazygit/pkg/gui/controllers/helpers.(*RefreshHelper).refreshView(0xc0008a2580, {0xe627a8, 0xc000018408})
/home/runner/work/lazygit/lazygit/pkg/gui/controllers/helpers/refresh_helper.go:736 +0x4c
github.com/jesseduffield/lazygit/pkg/gui/controllers/helpers.(*RefreshHelper).refreshRemotes(0xc0008a2580)
/home/runner/work/lazygit/lazygit/pkg/gui/controllers/helpers/refresh_helper.go:661 +0x19f
github.com/jesseduffield/lazygit/pkg/gui/controllers/helpers.(*RefreshHelper).Refresh.func2.9()
/home/runner/work/lazygit/lazygit/pkg/gui/controllers/helpers/refresh_helper.go:164 +0x17
github.com/jesseduffield/lazygit/pkg/gui/controllers/helpers.(*RefreshHelper).Refresh.func2.1.1({0x0?, 0x25?})
/home/runner/work/lazygit/lazygit/pkg/gui/controllers/helpers/refresh_helper.go:108 +0x13
github.com/jesseduffield/gocui.(*Gui).onWorkerAux(0xc0002c4700, 0x44695d?, {0xe54e38?, 0xc00032ac80?})
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:682 +0x6b
github.com/jesseduffield/gocui.(*Gui).OnWorker.func1()
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:669 +0x2b
created by github.com/jesseduffield/gocui.(*Gui).OnWorker in goroutine 1
/home/runner/work/lazygit/lazygit/vendor/github.com/jesseduffield/gocui/gui.go:668 +0x92
```