ENH: Add openslide to cpath conda environment

[ant0nsc]

Add openslide to hi-ml-cpath conda environment, so that code can use either cucim or openslide as backend.

[codecov]

Codecov Report

Merging #646 (c7d6d71) into main (bc32798) will increase coverage by 8.85%.
The diff coverage is n/a.

Flag	Coverage Δ
hi-ml-cpath	76.94% <ø> (+20.59%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...-ml-cpath/src/SSL/configs/PANDA_SimCLRContainer.py	57.89% <0.00%> (ø)
.../SSL/lightning_modules/byol/byol_moving_average.py	100.00% <0.00%> (ø)
hi-ml-cpath/src/SSL/ssl_augmentation_config.py	100.00% <0.00%> (ø)
...l-cpath/src/SSL/lightning_modules/simclr_module.py	100.00% <0.00%> (ø)
hi-ml-cpath/src/SSL/data/cifar_datasets.py	90.00% <0.00%> (ø)
hi-ml-cpath/src/SSL/configs/CovidContainers.py	87.50% <0.00%> (ø)
hi-ml-cpath/src/SSL/configs/CIFAR_SSL_configs.py	90.90% <0.00%> (ø)
hi-ml-cpath/src/SSL/data/io_util.py	75.86% <0.00%> (ø)
...c/SSL/lightning_containers/ssl_image_classifier.py	93.10% <0.00%> (ø)
.../src/SSL/lightning_modules/ssl_online_evaluator.py	89.79% <0.00%> (ø)
... and 35 more

[kenza-bouzid]

LGTM