Resets the image factories each time the collection is called

Former-commit-id: a07b10279c4d943f40fe62bf2e0c3a286476564a
Former-commit-id: 35da6f6df68103d1b3bfce47b17d56b3bda75ba3

src/ImageProcessor.UnitTests/ImageFactoryUnitTests.cs

@@ -668,6 +668,12 @@ namespace ImageProcessor.UnitTests
                 }
             }
 
+            // reset all the images whenever we call this
+            foreach (ImageFactory image in imagesFactories)
+            {
+                image.Reset();
+            }
+
             return imagesFactories;
         }