Remove even obsoleter code

Jellyfin.Api/Controllers/ImageController.cs

@@ -1901,8 +1901,7 @@ public class ImageController : BaseJellyfinApiController
             Blur = blur,
             BackgroundColor = backgroundColor,
             ForegroundLayer = foregroundLayer,
-            SupportedOutputFormats = outputFormats,
-            StrictCacheHandling = true
+            SupportedOutputFormats = outputFormats
         };
 
         return await GetImageResult(

MediaBrowser.Controller/Drawing/ImageProcessingOptions.cs

@@ -54,8 +54,6 @@ namespace MediaBrowser.Controller.Drawing
 
         public bool RequiresAutoOrientation { get; set; }
 
-        public bool StrictCacheHandling { get; set; }
-
         private bool HasDefaultOptions(string originalImagePath)
         {
             return HasDefaultOptionsWithoutSize(originalImagePath) &&