ci: Enable Swift tests in Ninja Multi-Config job on Windows

.gitlab/ci/configure_windows_vs2022_x64_ninja_multi.cmake

@@ -1,6 +1,7 @@
 if (NOT "$ENV{CMAKE_CI_NIGHTLY}" STREQUAL "")
   set(CMake_TEST_IAR_TOOLCHAINS "$ENV{CI_PROJECT_DIR}/.gitlab/iar" CACHE PATH "")
   set(CMake_TEST_ISPC "ON" CACHE STRING "")
+  set(CMake_TEST_Swift "ON" CACHE STRING "")
 endif()
 
 include("${CMAKE_CURRENT_LIST_DIR}/configure_windows_msvc_cxx_modules_common.cmake")

.gitlab/ci/env_windows_vs2022_x64_ninja_multi.ps1

@@ -1,6 +1,7 @@
 if ("$env:CMAKE_CI_NIGHTLY" -eq "true") {
   . ".gitlab/ci/iar-env.ps1"
   . ".gitlab/ci/ispc-env.ps1"
+  . ".gitlab/ci/swift-env.ps1"
 }
 
 . .gitlab/ci/ninja-env.ps1