install missing file command

.drone.yml

@@ -43,6 +43,10 @@ steps:
     image: mcr.microsoft.com/dotnet/sdk:6.0-focal
     failure: ignore
     commands:
+      - |
+        apt-get update
+        apt-get install -y file
+
       - |
         pwsh -NonInteractive -c "& {
           Import-Module './tools/DevDependency.psm1' -ErrorAction 'Stop';