[AI] "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" when cooking a project with validation enabled

The cook completes with a warning for "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" which causes many CI pipelines to fail as they use treat warnings as errors.

1. Create a clean TP_ThirdPerson project or use an existing project.
2. Cook the project, including the maps, with -RunAssetValidation or -RunMapValidation.

1. 1. Arguments I used "-run=cook -TargetPlatforms=Windows -CookAll -RunAssetValidation"

Expected Result: The cook completes successfully with no warnings (at least for navigation)

Actual Result: The cook completes with the null Navigation Repository warning

>    UnrealEditor-NavigationSystem.dll!UNavigationSystemV1::UNavigationSystemV1(const FObjectInitializer & ObjectInitializer) Line 947    C++
     UnrealEditor-CoreUObject.dll!StaticConstructObject_Internal(const FStaticConstructObjectParameters & Params) Line 4934    C++
     [Inline Frame] UnrealEditor-Engine.dll!NewObject(UObject *) Line 1835    C++
     UnrealEditor-Engine.dll!UNavigationSystemConfig::CreateAndConfigureNavigationSystem(UWorld & World) Line 35    C++
     UnrealEditor-Engine.dll!FNavigationSystem::AddNavigationSystemToWorld(UWorld & WorldOwner, const FNavigationSystemRunMode RunMode, UNavigationSystemConfig * NavigationSystemConfig, const bool bInitializeForWorld, const bool bOverridePreviousNavSys) Line 100    C++
     UnrealEditor-Engine.dll!UWorld::InitWorld(const FWorldInitializationValues IVS) Line 2249    C++
     UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::ValidateSourcePackage(UE::Cook::FPackageData & PackageData, UPackage * Package) Line 3323    C++
     UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::LoadPackageInQueue(UE::Cook::FPackageData & PackageData, unsigned int & ResultFlags, int & OutNumPushed) Line 3175    C++
     UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::PumpLoads(UE::Cook::FTickStackData & StackData, unsigned int DesiredQueueLength, int & OutNumPushed, bool & bOutBusy) Line 2998    C++
     [Inline Frame] UnrealEditor-UnrealEd.dll!IsEngineExitRequested() Line 390    C++
     UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::TickMainCookLoop(UE::Cook::FTickStackData & StackData) Line 1531    C++
     UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::TickCookByTheBook(const float TimeSlice, ECookTickFlags TickFlags) Line 1411    C++
     UnrealEditor-UnrealEd.dll!UCookCommandlet::RunCookByTheBookCook(UCookOnTheFlyServer * CookOnTheFlyServer, void * StartupOptionsAsVoid, ECookByTheBookOptions CookOptions) Line 595    C++
     UnrealEditor-UnrealEd.dll!UCookCommandlet::CookByTheBook(const TArray<ITargetPlatform *,TSizedDefaultAllocator<32>> & Platforms) Line 548    C++
     UnrealEditor-UnrealEd.dll!UCookCommandlet::Main(const FString & CmdLineParams) Line 268    C++
     UnrealEditor.exe!FEngineLoop::PreInitPostStartupScreen(const wchar_t * CmdLine) Line 4167    C++
     [Inline Frame] UnrealEditor.exe!FEngineLoop::PreInit(const wchar_t *) Line 4464    C++
     [Inline Frame] UnrealEditor.exe!EnginePreInit(const wchar_t *) Line 40    C++
     UnrealEditor.exe!GuardedMain(const wchar_t * CmdLine) Line 143    C++
     UnrealEditor.exe!LaunchWindowsStartup(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow, const wchar_t * CmdLine) Line 267    C++
     UnrealEditor.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * pCmdLine, int nCmdShow) Line 335    C++
     [Inline Frame] UnrealEditor.exe!invoke_main() Line 102    C++
     UnrealEditor.exe!__scrt_common_main_seh() Line 288    C++
     kernel32.dll!00007ff99f7e7374()    Unknown
     ntdll.dll!00007ff9a149cc91()    Unknown