Update AGIFORMER with Turkish benchmark

benchmark/metrics_english.json

@@ -0,0 +1,5 @@
+{
+  "train_bpc": [],
+  "val_bpc": [2.3478, 2.3301, 2.2900, 2.2814, 2.2808, 2.2578],
+  "steps": []
+}