Fix clippy warnings

[willemv]

Checklist

• cargo clippy reports no issues
• cargo doc reports no issues
• cargo deny issues have been fixed or added to deny.toml
• human-readable change descriptions added to the changelog under the "Unreleased" heading.
  • If the change does not affect the user (or is a process change), preface the change with "Internal:"
  • 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

[cwfitzgerald]

Thanks so much!