Lint for trailing comma in macro parameters

What it does

This proposed lint would detect and warn about unnecessary trailing commas in macro parameters. While a trailing comma in macro parameters is not an error in Rust, it can be superfluous and might not align with some coding style preferences.

Advantage

• Improved Readability: Removing unnecessary trailing commas can make the code clearer and easier to read.
• Consistency: Enforcing this style can help maintain a consistent coding standard across the codebase.

Drawbacks

No response

Example

println!("Hello, world!", );

Could be written as:

println!("Hello, world!");

No implementation file, test, or entry point is named in the issue. Start by locating existing Rust Clippy lints for macro invocation style, then compare their tests and configuration; done means the lint detects the unnecessary trailing comma shown in the example without treating valid macro syntax as an error.