Update test model id (#1785)

Author: echarlaix

tests/exporters/exporters_utils.py

@@ -129,7 +129,7 @@
         "hf-internal-testing/tiny-random-language_perceiver": ["fill-mask", "text-classification"],
         "hf-internal-testing/tiny-random-vision_perceiver_conv": ["image-classification"],
     },
-    "phi": "hf-internal-testing/tiny-random-PhiForCausalLM",
+    "phi": "echarlaix/tiny-random-PhiForCausalLM",
     "pix2struct": "fxmarty/pix2struct-tiny-random",
     # "rembert": "google/rembert",
     "poolformer": "hf-internal-testing/tiny-random-PoolFormerModel",