Fix RuntimeError not caught when torchcodec fails to load (#3987)

When datasets library has torchcodec installed but FFmpeg libraries
are missing, torchcodec raises a RuntimeError during import. The
exception handler only caught ImportError and AttributeError, causing
the error to propagate and crash Unsloth imports in environments
like Colab where FFmpeg may not be installed.

Co-authored-by: Daniel Han <danielhanchen@users.noreply.github.com>

unsloth/import_fixes.py

@@ -1051,5 +1051,5 @@ def patch_torchcodec_audio_decoder():
         from unsloth_zoo.dataset_utils import patch_torchcodec_audio_decoder as _patch
 
         _patch()
-    except (ImportError, AttributeError):
+    except (ImportError, AttributeError, RuntimeError):
         pass