fix: Update Rust style guide (Clippy lints part)

[stanislav-tkach]

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Description

The Rust style guide part about lints is somewhat outdated, so I have removed the parts that are no longer true and changed the description of integer_arithmetic lint that was renamed.

Related to: https://github.com/input-output-hk/catalyst-voices/issues/1467.

Type of change

This pull request only changes the documentation, so no additional testing is required.

Checklist

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules