UI/updater: Only run updater on Windows 10+

OBS Studio 28 no longer supports Windows 7, 8, or 8.1, and Qt 6 will
fail to run on those versions. Users on those systems being offered the
update will end up in a state where OBS will not run if they install the
update. Let's prevent the updater executable from running on those
versions to avoid that scenario.

UI/win-update/updater/updater.cpp

@@ -1873,6 +1873,18 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, LPWSTR lpCmdLine, int)
 
 	is32bit = wcsstr(cwd, L"bin\\32bit") != nullptr;
 
+	if (!IsWindows10OrGreater()) {
+		MessageBox(
+			nullptr,
+			L"OBS Studio 28 and newer no longer support Windows 7,"
+			L" Windows 8, or Windows 8.1. You can disable the"
+			L" following setting to opt out of future updates:"
+			L" Settings → General → General → Automatically check"
+			L" for updates on startup",
+			L"Unsupported Operating System", MB_ICONWARNING);
+		return 0;
+	}
+
 	if (!HasElevation()) {
 
 		WinHandle hMutex = OpenMutex(

UI/win-update/updater/updater.hpp

@@ -24,6 +24,7 @@
 #define ZLIB_CONST
 
 #include <windows.h>
+#include <versionhelpers.h>
 #include <winhttp.h>
 #include <commctrl.h>
 #include <Wincrypt.h>