.github/workflows: Migrate workflows to Blacksmith runners

.github/workflows/msbuild.yml

@@ -17,7 +17,7 @@ permissions:
 
 jobs:
   build:
-    runs-on: windows-latest
+    runs-on: blacksmith-4vcpu-windows-2025
     strategy:
       matrix:
         platform: [arm64, x64]

build.py

@@ -2,22 +2,32 @@
 import sys
 import shutil
 
-PROGRAM_FILES = os.environ["ProgramFiles"]
-VISUAL_STUDIO_INSTALLED_VERSION = 2022
-VISUAL_STUDIO_INSTALLED_VARIANT = ["Community", "Professional", "Enterprise"]
-
-MS_BUILD_PATH = '{}\\Microsoft Visual Studio\\{}\\{}\\MSBuild\\Current\\Bin\\MSBuild.exe'
-
-for variant in VISUAL_STUDIO_INSTALLED_VARIANT:
-    if os.path.exists(
-        MS_BUILD_PATH.format(
-            PROGRAM_FILES, VISUAL_STUDIO_INSTALLED_VERSION, variant
-        )
-    ):
-        MS_BUILD_PATH = MS_BUILD_PATH.format(
-            PROGRAM_FILES, VISUAL_STUDIO_INSTALLED_VERSION, variant
-        )
-        break
+PROGRAM_FILES_DIRS = [
+    d for d in (
+        os.environ.get("ProgramFiles"),
+        os.environ.get("ProgramFiles(x86)"),
+    ) if d
+]
+VISUAL_STUDIO_INSTALLED_VERSION = 2022
+VISUAL_STUDIO_INSTALLED_VARIANT = ["Community", "Professional", "Enterprise", "BuildTools"]
+
+MS_BUILD_PATH_TEMPLATE = '{}\\Microsoft Visual Studio\\{}\\{}\\MSBuild\\Current\\Bin\\MSBuild.exe'
+MS_BUILD_PATH = None
+
+for program_files in PROGRAM_FILES_DIRS:
+    for variant in VISUAL_STUDIO_INSTALLED_VARIANT:
+        candidate = MS_BUILD_PATH_TEMPLATE.format(
+            program_files, VISUAL_STUDIO_INSTALLED_VERSION, variant
+        )
+        if os.path.exists(candidate):
+            MS_BUILD_PATH = candidate
+            break
+    if MS_BUILD_PATH:
+        break
+
+if not MS_BUILD_PATH:
+    # Fall back to MSBuild on PATH (e.g. added by microsoft/setup-msbuild).
+    MS_BUILD_PATH = shutil.which("MSBuild") or shutil.which("MSBuild.exe") or "MSBuild.exe"
 
 PROJECT_SOLUTION_PATH = os.path.join(os.path.curdir, 'ArchWSL.sln')
 MS_BUILD_TARGET = "Build"