Remove unused functions

[hakonanes]

Description of the change

This PR removes the following deprecated datasets from the kikuchipy.data module:

• silicon_ebsd_moving_screen_in()
• silicon_ebsd_moving_screen_out5mm()
• silicon_ebsd_moving_screen_out10mm()

They were deprecated in v0.8 and replaced by si_ebsd_moving_screen(distance).

Progress of the PR

• [n/a] Docstrings for all functions
• [n/a] Unit tests with pytest for all lines
• [n/a] Clean code style by running black via pre-commit

For reviewers

• The PR title is short, concise, and will make sense 1 year later.
• New functions are imported in corresponding __init__.py.
• New features, API changes, and deprecations are mentioned in the unreleased
  section in CHANGELOG.rst.
• New contributors are added to release.py, .zenodo.json and
  .all-contributorsrc with the table regenerated.