skip torch versions < 2.5

Author: danielvegamyhre

test/float8/test_float8_utils.py

@@ -4,6 +4,10 @@
 import torch
 
 from torchao.float8.float8_utils import _round_scale_down_to_power_of_2
+from torchao.utils import TORCH_VERSION_AT_LEAST_2_5
+
+if not TORCH_VERSION_AT_LEAST_2_5:
+    pytest.skip("Unsupported PyTorch version", allow_module_level=True)
 
 
 # source for notable single-precision cases: