fix: Fix UnicodeDecodeError and pyarrow.lib.ArrowInvalid when loading

```cmd
UnicodeDecodeError: 'charmap' codec can't decode byte 0x8d in position 6265: character maps to <undefined>
```
Fix UnicodeDecodeError by forcing encoding to UTF-8 in _generate_examples.

```cmd
pyarrow.lib.ArrowInvalid: Integer value 2710988854 not in range: -2147483648 to 2147483647
```
Fix integer value out of bounds in stats_view or stats_downloads by using unsigned type.

unsplash-25k-photos.py

@@ -49,8 +49,8 @@ class Unsplash(datasets.GeneratorBasedBuilder):
                     'photo_location_longitude': datasets.Value("string"),
                     'photo_location_country': datasets.Value("string"),
                     'photo_location_city': datasets.Value("string"),
-                    'stats_views': datasets.Value("int32"),
-                    'stats_downloads': datasets.Value("int32"),
+                    'stats_views': datasets.Value("uint32"),
+                    'stats_downloads': datasets.Value("uint32"),
                     'ai_description': datasets.Value("string"),
                     'ai_primary_landmark_name': datasets.Value("string"),
                     'ai_primary_landmark_latitude': datasets.Value("string"),
@@ -80,7 +80,7 @@ class Unsplash(datasets.GeneratorBasedBuilder):
 
     def _generate_examples(self, filepath):
         """This function returns the examples in the raw (text) form."""
-        with open(filepath, "r") as f:
+        with open(filepath, "r", encoding="utf-8") as f:
             id_ = 0
             for line in f:
                 if id_ == 0: