STYLE: Trim trailing whitespaces

[fepegar]

This will be the first of a series of pull requests to fix issues flagged by pre-commit.

I first installed pre-commit:

$ pip install pre-commit
$ pre-commit install

Then,

$ pre-commit run --all-files trailing-whitespace
Trim Trailing Whitespace.................................................Failed
- hook id: trailing-whitespace
- exit code: 1
- files were modified by this hook

Fixing docs/deploy_on_aml.md
Fixing docs/environment.md
Fixing docs/bring_your_own_model.md
Fixing Tests/ML/reports/test_segmentation_report.py
Fixing docs/self_supervised_models.md
Fixing Tests/ML/models/test_scalar_model.py
Fixing docs/creating_dataset.md
Fixing docs/WSL.md
Fixing docs/sample_tasks.md
Fixing docs/releases.md
Fixing InnerEye/ML/configs/classification/DummyClassification.py
Fixing InnerEye/ML/SSL/utils.py
Fixing InnerEye/ML/configs/other/HelloContainer.py
Fixing InnerEye/ML/dataset/scalar_dataset.py
Fixing Tests/ML/test_data/Val_outliers.txt
Fixing InnerEye/ML/lightning_container.py
Fixing Tests/ML/test_lightning_containers.py
Fixing docs/move_model.md
Fixing sphinx-docs/README.md
Fixing SECURITY.md
Fixing Tests/SSL/test_ssl_containers.py
Fixing InnerEye/ML/configs/segmentation/HelloWorld.py
Fixing Tests/ML/models/test_parallel.py
Fixing .github/workflows/linting_and_hello_world.yml
Fixing docs/testing.md
Fixing docs/model_diagnostics.md
Fixing Tests/ML/test_data/Val_outliers_pruned.txt