CI: Use Windows 11 SDK 10.0.22621.0

Before 6c590805e88755f70ad62ffbb217ad8ace09563b, builds on Windows would
automatically select a Windows SDK using CMake's rules:

https://cmake.org/cmake/help/v3.25/variable/CMAKE_VS_WINDOWS_TARGET_PLATFORM_VERSION.html
https://cmake.org/cmake/help/v3.30/variable/CMAKE_VS_WINDOWS_TARGET_PLATFORM_VERSION.html
https://cmake.org/cmake/help/v3.30/policy/CMP0149.html

This meant that CI Windows builds would end up using SDK 10.0.20348.0
because that matched the runner's OS version exactly. Locally, if a
Windows SDK version that exactly matched the host system version was not
installed, CMake would select the latest Windows SDK available. This
caused some observed differences in build success between CI and local
builds if a newer SDK was used locally.

The Windows runners have the 10.0.22621.0 SDK installed, so let's
specifically select that.

CMakePresets.json

@@ -98,7 +98,7 @@
         "lhs": "${hostSystemName}",
         "rhs": "Windows"
       },
-      "architecture": "x64,version=10.0.20348",
+      "architecture": "x64,version=10.0.22621",
       "binaryDir": "${sourceDir}/build_x64",
       "generator": "Visual Studio 17 2022",
       "cacheVariables": {