fix: Use project_plugins to avoid dep conflicts

[jrogov]

When including project- and build-related plugins under plugins key in rebar.config there's a risk of conflict with top-level project config when lib is fetched as a dependency.

Rebar has a mechanism of project_plugins, where plugins are only fetched and used on same-level issue of rebar3 command.

More info: https://rebar3.readme.io/docs/using-available-plugins#project-plugins-and-overriding-commands Encounter: https://github.com/project-fifo/rebar3_lint/issues/42