Remove requirement for composer/installers 1.0 from composer.libraries.json

Problem/Motivation

There's no need to specify a version dependency on composer/installers 1.0 in composer.libraries.json, and while it used to be innocuous, now that composer/installers 2.0 is out, it turns out to be a nuisance.

Steps to reproduce

Try to install the toc library using composer.libraries.json when using composer/installers 2.0

Proposed resolution

Remove the dependency.

Remaining tasks

User interface changes

API changes

Data model changes