cannot set init parameter to pca

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I have installed umap-learn==0.5.3 with python 3.10

```
% pip list
Package Version
--------------- -------
colorama 0.4.6
joblib 1.2.0
llvmlite 0.39.1
numba 0.56.3
numpy 1.23.4
pandas 2.0.0
pip 22.3.1
pynndescent 0.5.8
python-dateutil 2.8.2
pytz 2023.3
scikit-learn 1.1.3
scipy 1.9.3
setuptools 65.5.1
six 1.16.0
threadpoolctl 3.1.0
tqdm 4.64.1
tzdata 2023.3
umap-learn 0.5.3
wheel 0.38.4
```

tried to run a simple umap conversion with init parameter set to **'pca'**

```
import umap as umap
from umap import UMAP
umap_nd = UMAP(n_components=components,
init='pca',
random_state=42,
n_neighbors=n_neighbors,
min_dist=min_dist
)
print(umap.__version__)
proj_nd = umap_nd.fit(data_df.values)
```

the print output is saying its version **0.5.3**
but it is giving error as below (sharing snippet)

```
proj_nd = umap_nd.fit(data_df.values)
File "/home/.pyenv/versions/anaconda3-5.3.1/envs/project-p/lib/python3.10/site-packages/umap/umap_.py", line 2290, in fit
self._validate_parameters()
File "/home/versions/anaconda3-5.3.1/envs/project-p/lib/python3.10/site-packages/umap/umap_.py", line 1704, in _validate_parameters
raise ValueError('string init values must be "spectral" or "random"')
ValueError: string init values must be "spectral" or "random"
```

Reproduce the reported UMAP 0.5.3 failure with Python 3.10 and init='pca' using the provided environment. Inspect umap/umap_.py around _validate_parameters at line 1704, then determine whether PCA initialization should be supported; done when the intended behavior is enforced and covered by the relevant validation or regression test.

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