Repository: pykeen/pykeen
Issue: `load_triples` and `np.loadtxt` might load incorrect data
Root cause: External Dependency Breakage

### Describe the bug

I am loading a dataset from the txt file where triples are already expressed as integer IDs [Link to the txt file (Google Drive)](https://drive.google.com/file/d/1iuFnePMk_tAnS-OZZPrLiiuxLjEMr4Ba/view?usp=sharing).

I am 100% sure the file has all unique triples w/o repetitions. However, when I load the file with `pykeen.utils.load_triples` and then send the result to `TriplesFactory.from_labeled_triples` I get fewer triples and unique entities as expected. Possibly, the problem might be in the `np.loadtxt` function which loads incorrect strings from the input file. Particular examples from the code below:

Some original triples from the file
```
10280	50	51
51	51	10280
```

Triples after `np.loadtxt` - notice 10280 turned into '1028'
```
'1028'	'50'	'51'
'51'	'51'	'1028'
```

If I replace `np.loadtxt` with a custom dummy loader (code is below) the stats (triples and num entities) get back to what's expected.

### How to reproduce


```python
# Download the train_graph.txt
import numpy as np

from pykeen.datasets.base import TriplesFactory
from pykeen.triples.utils import load_triples

def dummy_loader(fname: str) -> np.ndarray:
    triples = []
    with open(fname, "r") as fin:
        for line in fin:
            triple = [x for x in line.split()]
            triples.append(triple)

    return np.array(triples, dtype=np.str)

ds1 = load_triples("train_graph.txt")   # 392672 lines
ds2 = dummy_loader("train_graph.txt")  # 392672 lines

print(np.unique(ds1, axis=0).shape)  # (390668, 3) <- INCORRECT
print(np.unique(ds2, axis=0).shape)  # (392762, 3) <- correct

factory1 = TriplesFactory.from_labeled_triples(triples=ds1, filter_out_candidate_inverse_relations=False, create_inverse_triples=False)
factory2 = TriplesFactory.from_labeled_triples(triples=ds2, filter_out_candidate_inverse_relations=False, create_inverse_triples=False)

print(factory1.num_entities) # 10000 <- INCORRECT
print(factory2.num_entities) # 11567 <- correct

```

### Environment

| Key             | Value                    |
|-----------------|--------------------------|
| OS              | posix                    |
| Platform        | Darwin                   |
| Release         | 20.3.0                   |
| Time            | Mon Dec 20 17:45:57 2021 |
| Python          | 3.8.12                   |
| PyKEEN          | 1.6.0                    |
| PyKEEN Hash     | UNHASHED                 |
| PyKEEN Branch   |                          |
| PyTorch         | 1.10.0                   |
| CUDA Available? | false                    |
| CUDA Version    | N/A                      |
| cuDNN Version   | N/A                      |

### Additional information

_No response_

I always had my suspicions about the numpy loader

likely related https://github.com/numpy/numpy/issues/17277 . I encountered a similar error in another project, where I switched to [`pandas.read_csv`](https://pandas.pydata.org/docs/reference/api/pandas.read_csv.html) instead which did not seem to be affected by the problem.