wsl: skip distributions that indicate they are "Modern" (#18183)

(cherry picked from commit 00ff803)
Service-Card-Id: PVTI_lADOAF3p4s4AmhmszgUu4sc
Service-Version: 1.21

Author: DHowett

src/cascadia/TerminalSettingsModel/WslDistroGenerator.cpp

@@ -19,6 +19,7 @@ static constexpr std::wstring_view RancherDistributionPrefix{ L"rancher-desktop"
 //     ⌞ DistributionName: {the name}
 static constexpr wchar_t RegKeyLxss[] = L"Software\\Microsoft\\Windows\\CurrentVersion\\Lxss";
 static constexpr wchar_t RegKeyDistroName[] = L"DistributionName";
+static constexpr wchar_t RegKeyModern[] = L"Modern";
 
 using namespace ::Microsoft::Terminal::Settings::Model;
 using namespace winrt::Microsoft::Terminal::Settings::Model;
@@ -188,6 +189,12 @@ static bool getWslNames(const wil::unique_hkey& wslRootKey,
             continue;
         }
 
+        const auto modernValue{ wil::reg::try_get_value<uint32_t>(distroKey.get(), RegKeyModern) };
+        if (modernValue.value_or(0u) == 1u)
+        {
+            continue;
+        }
+
         std::wstring buffer;
         auto result = wil::AdaptFixedSizeToAllocatedResult<std::wstring, 256>(buffer, [&](PWSTR value, size_t valueLength, size_t* valueLengthNeededWithNull) -> HRESULT {
             auto length = gsl::narrow<DWORD>(valueLength * sizeof(wchar_t));

src/cascadia/TerminalSettingsModel/pch.h

@@ -24,6 +24,7 @@
 #endif
 
 #include <wil/cppwinrt.h>
+#include <wil/registry.h>
 
 #include <winrt/Windows.ApplicationModel.AppExtensions.h>
 #include <winrt/Windows.ApplicationModel.h>