Remove Windows 32-bit ARM build from CI

This architecture is deprecated and is now failing with:
Windows SDK 10.0.22621.0 : 'C:\Program Files (x86)\Windows Kits\10\include\10.0.22621.0\um' not found or was incomplete

Fixes https://github.com/libsdl-org/SDL/issues/13949

.github/workflows/create-test-plan.py

@@ -20,7 +20,6 @@ class AppleArch(Enum):
 class MsvcArch(Enum):
     X86 = "x86"
     X64 = "x64"
-    Arm32 = "arm"
     Arm64 = "arm64"
 
 
@@ -110,7 +109,6 @@ JOB_SPECS = {
     "msvc-x86": JobSpec(name="Windows (MSVC, x86)",                         os=JobOs.WindowsLatest,     platform=SdlPlatform.Msvc,        artifact="SDL-VC-x86",             msvc_arch=MsvcArch.X86,   msvc_project="VisualC/SDL.sln", ),
     "msvc-clang-x64": JobSpec(name="Windows (MSVC, clang-cl x64)",          os=JobOs.WindowsLatest,     platform=SdlPlatform.Msvc,        artifact="SDL-clang-cl-x64",       msvc_arch=MsvcArch.X64,   clang_cl=True, ),
     "msvc-clang-x86": JobSpec(name="Windows (MSVC, clang-cl x86)",          os=JobOs.WindowsLatest,     platform=SdlPlatform.Msvc,        artifact="SDL-clang-cl-x86",       msvc_arch=MsvcArch.X86,   clang_cl=True, ),
-    "msvc-arm32": JobSpec(name="Windows (MSVC, ARM)",                       os=JobOs.WindowsLatest,     platform=SdlPlatform.Msvc,        artifact="SDL-VC-arm32",           msvc_arch=MsvcArch.Arm32, ),
     "msvc-arm64": JobSpec(name="Windows (MSVC, ARM64)",                     os=JobOs.WindowsLatest,     platform=SdlPlatform.Msvc,        artifact="SDL-VC-arm64",           msvc_arch=MsvcArch.Arm64, ),
     "msvc-gdk-x64": JobSpec(name="GDK (MSVC, x64)",                         os=JobOs.WindowsLatest,     platform=SdlPlatform.Msvc,        artifact="SDL-VC-GDK",             msvc_arch=MsvcArch.X64,   msvc_project="VisualC-GDK/SDL.sln", gdk=True, no_cmake=True, ),
     "ubuntu-22.04": JobSpec(name="Ubuntu 22.04",                            os=JobOs.Ubuntu22_04,       platform=SdlPlatform.Linux,       artifact="SDL-ubuntu22.04", ),
@@ -416,10 +414,6 @@ def spec_to_job(spec: JobSpec, key: str, trackmem_symbol_names: bool) -> JobDeta
                     job.msvc_vcvars_arch = "x64_x86"
                 case MsvcArch.X64:
                     job.msvc_vcvars_arch = "x64"
-                case MsvcArch.Arm32:
-                    job.msvc_vcvars_arch = "x64_arm"
-                    job.msvc_vcvars_sdk = "10.0.22621.0"  # 10.0.26100.0 dropped ARM32 um and ucrt libraries
-                    job.run_tests = False
                 case MsvcArch.Arm64:
                     job.msvc_vcvars_arch = "x64_arm64"
                     job.run_tests = False