axum-extra should depend on tower with default_features = false

[davidpdrsn]

Otherwise tower will enable tracing's log feature, which users might not want (I wish tower didn't do this). Changing this technically a breaking change but might be acceptable in a minor release 🤷

Probably not worth adding a tower-log feature like axum has, to axum-extra, since users who depend on axum-extra probably also depends on axum so they can enable the feature there.