Editor crash when building lighting and world partition minimap

It is possible for an editor crash to occur if a build is running (Lightmass in this case) and another is launched such as Build World Partition Minimap (as well as HLOD and Spline builders). This is due to `FEditorFileUtils::LoadMap` being called after the World Partition builder completes, which results in an access violation.

Within `FEditorFileUtils::LoadMap` there is a call to `GEditor->WarnIfLightingBuildIsCurrentlyRunning()` which seems it would prevent the problem, but it happens after the builder completes and calls `LoadMap` from the World Partition builder.

1. File > New Level.. > Empty Open World
2. Add a new static mesh actor such as a cube
3. In World Settings uncheck Force No Precomputed Lighting
4. File > Save All and provide a level name
5. Build > Build Lighting Only
6. Before the lighting build completes, in the World Partition window choose Build > Build World Partition Minimap
7. Cancel the minimap build, or wait for it to complete
8. Wait for the lighting build to complete and click Apply Now

Observe: The editor process will crash due to an access violation.
Expected: The editor process should not crash.

>UnrealEditor-NavigationSystem.dll!UObjectBaseUtility::IsA<UNavigationSystemV1>() Line 625 C++
[Inline Frame] UnrealEditor-NavigationSystem.dll!Cast(UNavigationSystemBase *) Line 160 C++
[Inline Frame] UnrealEditor-NavigationSystem.dll!FNavigationSystem::GetCurrent(UWorld *) Line 117 C++
[Inline Frame] UnrealEditor-NavigationSystem.dll!UNavigationSystemV1::

{ctor}::__l2::FDelegatesInitializer::{ctor}

::__l2::<lambda_24>::operator()(UWorld &) Line 864 C++
[Inline Frame] UnrealEditor-NavigationSystem.dll!Invoke(UNavigationSystemV1::

{ctor}::__l2::FDelegatesInitializer::{ctor}

::__l2::<lambda_24> &) Line 47 C++
[Inline Frame] UnrealEditor-NavigationSystem.dll!UE::Core::Private::Tuple::TTupleBase<TIntegerSequence<unsigned int>>::ApplyAfter(UNavigationSystemV1::

{ctor}::__l2::FDelegatesInitializer::{ctor}

::__l2::<lambda_24> &) Line 317 C++
UnrealEditor-NavigationSystem.dll!TBaseFunctorDelegateInstance<void __cdecl(UWorld &,unsigned char),FDefaultDelegateUserPolicy,``UNavigationSystemV1::UNavigationSystemV1'::`2'::FDelegatesInitializer::FDelegatesInitializer'::`2'::<lambda_24>>::Execute(UWorld & <Params_0>, unsigned char <Params_1>) Line 864 C++
[Inline Frame] UnrealEditor-Engine.dll!TDelegate<void __cdecl(UWorld &,unsigned char),FDefaultDelegateUserPolicy>::Execute(UWorld & <Params_0>, unsigned char <Params_1>) Line 613 C++
UnrealEditor-Engine.dll!FNavigationLockContext::LockUpdates() Line 372 C++
[Inline Frame] UnrealEditor-UnrealEd.dll!FNavigationLockContext::

{ctor}

(UWorld *) Line 75 C++
UnrealEditor-UnrealEd.dll!FStaticLightingManager::ProcessLightingData() Line 181 C++
UnrealEditor-UnrealEd.dll!FStaticLightingSystem::UpdateLightingBuild() Line 2643 C++
UnrealEditor-UnrealEd.dll!FStaticLightingManager::UpdateBuildLighting() Line 372 C++
UnrealEditor-UnrealEd.dll!UEditorEngine::UpdateBuildLighting() Line 2785 C++
UnrealEditor.exe!FEngineLoop::Tick() Line 5877 C++
[Inline Frame] UnrealEditor.exe!EngineTick() Line 69 C++
UnrealEditor.exe!GuardedMain(const wchar_t * CmdLine) Line 188 C++
UnrealEditor.exe!LaunchWindowsStartup(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow, const wchar_t * CmdLine) Line 266 C++
UnrealEditor.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * pCmdLine, int nCmdShow) Line 317 C++
[Inline Frame] UnrealEditor.exe!invoke_main() Line 102 C++
UnrealEditor.exe!__scrt_common_main_seh() Line 288 C++
kernel32.dll!00007ffe1307e8d7() Unknown
ntdll.dll!00007ffe13cf14fc() Unknown