Fix clippy warnings

[willemv]

Checklist

• [x] cargo clippy reports no issues
• [x] cargo doc reports no issues
• [x] cargo deny issues have been fixed or added to deny.toml
• [x] human-readable change descriptions added to the changelog under the "Unreleased" heading.
  • [x] If the change does not affect the user (or is a process change), preface the change with "Internal:"
  • [x] Add credit to yourself for each change: Added new functionality @githubname.

Description

Recent clippy versions warn about unnecessary borrows. This PR fixes the new warnings.

Related Issues

[willemv]

The failing cargo deny is fixed by the upgrade to wgpu 0.10, see #66