fix: Update Rust style guide (Clippy lints part)

[stanislav-tkach]

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The Rust style guide part about lints is somewhat outdated, so I have removed the parts that are no longer true and changed the description of integer_arithmetic lint that was renamed.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: input-output-hk/catalyst-voices#1467.

Type of change

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

Checklist

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