Fix version comparison issue (#18)

# Description

The version comparison expression miss reference the .release property from the version object. This lead to compare between the tuple and the string

# Error message
```
The 8-bit optimizer is not available on your device, only available on CUDA for now.
🦥 Unsloth: Will patch your computer to enable 2x faster free finetuning.
Traceback (most recent call last):
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/unsloth_validation/run.py", line 1, in <module>
    import unsloth
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/v/lib/python3.10/site-packages/unsloth/__init__.py", line 235, in <module>
    from .models import *
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/v/lib/python3.10/site-packages/unsloth/models/__init__.py", line 15, in <module>
    from .llama     import FastLlamaModel
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/v/lib/python3.10/site-packages/unsloth/models/llama.py", line 23, in <module>
    from ._utils import *
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/v/lib/python3.10/site-packages/unsloth/models/_utils.py", line 89, in <module>
    from unsloth_zoo.patching_utils import (
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/v/lib/python3.10/site-packages/unsloth_zoo/patching_utils.py", line 629, in <module>
    import transformers.integrations.bitsandbytes
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/v/lib/python3.10/site-packages/transformers/integrations/bitsandbytes.py", line 20, in <module>
    import bitsandbytes as bnb
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/bitsandbytes/bitsandbytes/__init__.py", line 39, in <module>
    from .backends.xpu import ops as xpu_ops
  File "/home/erxin/jenkins/workspace/Unsloth_Benchmark/bitsandbytes/bitsandbytes/backends/xpu/ops.py", line 17, in <module>
    if version.parse(torch.__version__).release >= version.parse("2.9"):
TypeError: '>=' not supported between instances of 'tuple' and 'Version'
```

Author: shangerxin

bitsandbytes/backends/xpu/ops.py

@@ -14,7 +14,7 @@
 logger = logging.getLogger(__name__)
 
 # _int_mm is available in torch starting from 2.9 version
-if version.parse(torch.__version__).release >= version.parse("2.9"):
+if version.parse(torch.__version__).release >= version.parse("2.9").release:
 
     @register_kernel("bitsandbytes::int8_linear_matmul", "xpu")
     def _(A: torch.Tensor, B: torch.Tensor):