dep: Use smol-toml instead of toml (#164)

Fixed #162 #163

The former is listed on
https://github.com/toml-lang/toml/wiki#implementations and is toml 1.0
compliant.

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

Author: NobodyXu