Fix PowerShell script issues: replace pushd/popd aliases and remove unused variable

scripts/create_release.ps1

@@ -64,7 +64,7 @@ Write-Host "Build erfolgreich abgeschlossen!" -ForegroundColor Green
 # Tests ausführen
 Write-Host "Führe Tests aus..." -ForegroundColor Yellow
 if (Test-Path "build\CTestTestfile.cmake") {
-    pushd build
+    Push-Location build
     try {
         ctest -C Release --output-on-failure
         if ($LASTEXITCODE -ne 0) {
@@ -72,7 +72,7 @@ if (Test-Path "build\CTestTestfile.cmake") {
             exit 1
         }
     } finally {
-        popd
+        Pop-Location
     }
     Write-Host "Tests erfolgreich." -ForegroundColor Green
 } else {
@@ -310,7 +310,7 @@ if (Test-Path $distPath) {
             }
             
             try {
-                $uploadResponse = Invoke-RestMethod -Uri $uploadUri -Method Post -Headers $uploadHeaders -Body $body
+                Invoke-RestMethod -Uri $uploadUri -Method Post -Headers $uploadHeaders -Body $body | Out-Null
                 Write-Host "  ✓ $($artifact.Name) erfolgreich hochgeladen" -ForegroundColor Green
             } catch {
                 Write-Host "  ✗ Fehler beim Hochladen von $($artifact.Name): $($_.Exception.Message)" -ForegroundColor Red