config paths that start with ./ are not valid as hf:// accessed repos, but are valid when accessed locally

### Describe the bug

```
- config_name: some_config
data_files:
- split: train
path:
- images/xyz/*.jpg
```
will correctly download but

```
- config_name: some_config
data_files:
- split: train
path:
- ./images/xyz/*.jpg
```
will error with `FileNotFoundError` due to improper url joining. `load_dataset` on the same directory locally works fine.

### Steps to reproduce the bug

1. create a README.md with the front matter of the form

```
- config_name: some_config
data_files:
- split: train
path:
- ./images/xyz/*.jpg
```

2. `touch ./images/xyz/1.jpg`
3. Observe this directory loads with `load_dataset("filesystem_path", "some_config")` correctly.
4. Observe exceptions when you load this with `load_dataset("repoid/filesystem_path", "some_config")`

### Expected behavior

`./` prefix should be interpreted correctly

### Environment info

datasets 4.0.0
datasets 3.4.0

reproduce