Prepare to distribute standalone windows executable

This will be useful for our automated test riggig, and may be useful for
advanced users who want to "roll their own" system service

scripts/build_windows.ps1

@@ -60,6 +60,7 @@ function buildOllama() {
             /csp "Google Cloud KMS Provider" /kc ${env:KEY_CONTAINER} ollama.exe
         if ($LASTEXITCODE -ne 0) { exit($LASTEXITCODE)}
     }
+    cp .\ollama.exe .\dist\ollama-windows-amd64.exe
 }
 
 function buildApp() {