update powershell script

Author: tmthecoder

.github/workflows/dargon2_library-builder.yml

@@ -102,15 +102,14 @@ jobs:
         run: Copy-Item “argon2_library\vs2015\build\Argon2OptDll.dll” -Destination “lib\src\blobs\libargon2-win.dll”
       - name: Check if there are changes
         run: |
-          function check() {
-            if [[ -z "$(git status --porcelain)" ]];
-            then
-              echo "0"
-            else
-              echo "1"
-            fi
-          }
-          echo "CHANGED=$(check)" >> $GITHUB_ENV
+            $status = git status --porcelain
+            $num = 0
+            if ($status -eq "") {
+              Set-Variable -Name "num" -Value "0"
+            } else { 
+              Set-Variable -Name "num" -Value "1"
+            }
+          echo "CHANGED=$num" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf-8 -Append
       - name: Push if Changed
         if: ${{ env.CHANGED == '1' }}
         run: |