Update supported file name extensions for art

Art read from external files supports more formats than previously
listed here. Amend the list accordingly.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>

Plugins/TagLib/TagLibMetadataReader.m

@@ -214,7 +214,7 @@
 			// Gather list of candidate image files
 
 			NSArray *fileNames = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:path error:nil];
-			NSArray *types = @[@"jpg", @"jpeg", @"png"];
+			NSArray *types = @[@"jpg", @"jpeg", @"png", @"gif", @"webp", @"avif"];
 			NSArray *imageFileNames = [fileNames pathsMatchingExtensions:types];
 
 			for(NSString *fileName in imageFileNames) {