Readme states dependency but not enforced by blueprint

[Rotzbua]

Problem

The readme states that the plugin requires the error plugin, but is not required in the blueprint.

Reference

NOTE: This plugin is a modular component for Grav which requires Grav, the Error and Problems plugins, and a theme to be installed in order to operate.

https://github.com/getgrav/grav-plugin-problems/tree/2.1.2?tab=readme-ov-file#manual-installation

Not required in:

https://github.com/getgrav/grav-plugin-problems/blob/2.1.2/blueprints.yaml