lint-commit-message failing on unexpected namespace

[RafaelGSS]

I noticed we've been using agents as namespace (e.g 3913f0e). But, this is not valid as the namespace is validated against this set of rules https://github.com/nodejs/core-validate-commit/blob/5aa959cdd971d8426b4d7f48ea2ef95cdf4242d9/lib/rules/subsystem.js#L3.

So, if we want to enforce full green CI on PRs, we should either fork that repository and include our custom set of namespaces or just use generic ones, such as src or lib.

cc: @santigimeno