Removed execution mode field in pixel specific processor

src/ImageSharp/Processing/Processors/Convolution/BokehBlurProcessor{TPixel}.cs

@@ -36,11 +36,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
         /// </summary>
         private readonly float gamma;
 
-        /// <summary>
-        /// The execution mode to use when applying the effect
-        /// </summary>
-        private readonly BokehBlurExecutionMode executionMode;
-
         /// <summary>
         /// The maximum size of the kernel in either direction
         /// </summary>
@@ -84,7 +79,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
             this.kernelSize = (this.radius * 2) + 1;
             this.componentsCount = definition.Components;
             this.gamma = definition.Gamma;
-            this.executionMode = definition.ExecutionMode;
 
             // Reuse the initialized values from the cache, if possible
             var parameters = new BokehBlurParameters(this.radius, this.componentsCount);
@@ -396,12 +390,6 @@ namespace SixLabors.ImageSharp.Processing.Processors.Convolution
             var workingRectangle = Rectangle.FromLTRB(startX, startY, endX, endY);
             int width = workingRectangle.Width;
 
-            if (this.executionMode == BokehBlurExecutionMode.PreferLowMemoryUsage)
-            {
-                configuration = configuration.Clone();
-                configuration.MaxDegreeOfParallelism = 1;
-            }
-
             ParallelHelper.IterateRows(
                 workingRectangle,
                 configuration,