Remove overlay stability test to improve test suite efficiency

Source/QuestPDF.UnitTests/DocumentOperationTests.cs

@@ -55,35 +55,6 @@ public class DocumentOperationTests
             .Save("operation-overlay.pdf");
     }
     
-    [Test]
-    public void OverlayStabilityTest()
-    {
-        GenerateSampleDocument("overlay-watermark.pdf", Colors.Green.Medium, 5);
-        
-        foreach (var i in Enumerable.Range(1, 1_000_000))
-        {
-            if (i % 1000 == 0)
-                Console.WriteLine($"Overlay stability test: {i} iterations completed.");
-            
-            var input = $"overlay-main-{i}.pdf";
-            var output = $"operation-overlay-{i}.pdf";
-            
-            GenerateSampleDocument(input, Colors.Red.Medium, 10);
-        
-            DocumentOperation
-                .LoadFile(input)
-                .OverlayFile(new DocumentOperation.LayerConfiguration
-                {
-                    FilePath = "overlay-watermark.pdf"
-                })
-                .Save(output);
-            
-            File.Delete(input);
-            File.Delete(output);
-        }
-
-    }
-    
     [Test]
     public void UnderlayTest()
     {