Make sure load() returns Path

Fixes manual forward unit test:

```
>           ckpt_weights: Path = load(ckpt_name) / "weights"
E           TypeError: unsupported operand type(s) for /: 'str' and 'str'

sub-packages/bionemo-evo2/tests/bionemo/evo2/test_evo2.py:505: TypeError
```

Signed-off-by: Anton Vorontsov <avorontsov@nvidia.com>

Author: antonvnv

sub-packages/bionemo-core/src/bionemo/core/data/load.py

@@ -203,7 +203,7 @@ def load(
     if checked.exists():
         path = checked.read_text()
         logger.debug(f"Using cached {path=} from {checked=}")
-        return path
+        return Path(path)
 
     download = pooch.retrieve(
         url=str(url),