Function remove_decorators 

pub fn remove_decorators(
    source: &str,
    before_version: Option<&str>,
    remove_all: bool,
    current_version: Option<&str>,
) -> Result<(usize, String)>

Remove @replace_me decorated functions from source code

This removes entire functions decorated with @replace_me, not just the decorators. This should only be used after migration is complete and library authors want to clean up their codebase.

Returns a tuple of (removed_count, resulting_source)