Try to add dirent on Windows/Arm

Author: willend

.github/workflows/mcstas-basictest.yml

@@ -81,6 +81,7 @@ jobs:
         choco install winflexbison3
         choco install wget
         if [ "$CC" == "gcc.exe" ]; then choco install mingw; fi
+        if [ "$CC" == "cl.exe" ]; then choco install dirent; fi
         pip install mslex PyYAML ply ncrystal mcpl mcpl-extra psutil
 
     - name: Setup (Windows Intel)