clippy.toml lists the std::env readers (var, var_os, vars, vars_os,
set_var, remove_var, args, args_os, current_exe, temp_dir, home_dir) and
libc::getenv as disallowed methods, and lib.rs forbids allowing them back.
main.rs and the self-spawning integration test carry the only allows.
The forge probe's environment sweep and its 22 guessed variable names go:
the lint covers a variable of any name, so the list was a second, weaker
path for the same rule.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>