fix token state json and mistral tokenizer issue (#3522) [skip ci]

* fix token state json and mistral tokenizer issue

* centralize constants

* forgot to commit constants file

* Fix weakref in pickling relora state dict

* make curl a bit quieter so it doesn't log 2K lines

* fix path traversal for olmoe test

* more test fixes that weren't flagged previously

* chore: lint

* skip tests that fail b/c of OutOfResources

* scattermoe as slow tests

* update fbgemm-genai for torch 2.10

tests/e2e/test_optimizers.py

@@ -298,6 +298,7 @@ class TestCustomOptimizers(unittest.TestCase):
     ],
 )
 def test_flash_optimizers(tmp_path, optimizer_name, expected_class, learning_rate):
+    pytest.importorskip("flashoptim")
     temp_dir = str(tmp_path)
     cfg = DictDefault(
         {