use `Image.Resampling` namespace for PIL mapping

PIL shows a deprecation warning when accessing resampling constants via the `Image` namespace. The suggested namespace is `Image.Resampling`. This commit updates `_pil_interpolation_to_str` to use the `Image.Resampling` namespace.

```
/tmp/ipykernel_11959/698124036.py:2: DeprecationWarning: NEAREST is deprecated and will be removed in Pillow 10 (2023-07-01). Use Resampling.NEAREST or Dither.NONE instead.
  Image.NEAREST: 'nearest',
/tmp/ipykernel_11959/698124036.py:3: DeprecationWarning: BILINEAR is deprecated and will be removed in Pillow 10 (2023-07-01). Use Resampling.BILINEAR instead.
  Image.BILINEAR: 'bilinear',
/tmp/ipykernel_11959/698124036.py:4: DeprecationWarning: BICUBIC is deprecated and will be removed in Pillow 10 (2023-07-01). Use Resampling.BICUBIC instead.
  Image.BICUBIC: 'bicubic',
/tmp/ipykernel_11959/698124036.py:5: DeprecationWarning: BOX is deprecated and will be removed in Pillow 10 (2023-07-01). Use Resampling.BOX instead.
  Image.BOX: 'box',
/tmp/ipykernel_11959/698124036.py:6: DeprecationWarning: HAMMING is deprecated and will be removed in Pillow 10 (2023-07-01). Use Resampling.HAMMING instead.
  Image.HAMMING: 'hamming',
/tmp/ipykernel_11959/698124036.py:7: DeprecationWarning: LANCZOS is deprecated and will be removed in Pillow 10 (2023-07-01). Use Resampling.LANCZOS instead.
  Image.LANCZOS: 'lanczos',
```

timm/data/transforms.py

@@ -36,12 +36,12 @@ class ToTensor:
 
 
 _pil_interpolation_to_str = {
-    Image.NEAREST: 'nearest',
+    Image.Resampling.NEAREST: 'nearest',
-    Image.BILINEAR: 'bilinear',
+    Image.Resampling.BILINEAR: 'bilinear',
-    Image.BICUBIC: 'bicubic',
+    Image.Resampling.BICUBIC: 'bicubic',
-    Image.BOX: 'box',
+    Image.Resampling.BOX: 'box',
-    Image.HAMMING: 'hamming',
+    Image.Resampling.HAMMING: 'hamming',
-    Image.LANCZOS: 'lanczos',
+    Image.Resampling.LANCZOS: 'lanczos',
 }
 _str_to_pil_interpolation = {b: a for a, b in _pil_interpolation_to_str.items()}