Improvement: Requirements process does not mention the role contributor writes the requirements

### What

See: https://eclipse-score.github.io/process_description/main/process_areas/requirements_engineering/requirements_concept.html#stakeholders-for-the-requirements requires role contributor as the in the stakeholder list there is no explicit stakeholder involved writing the requirement.

### How

_No response_

### Estimates for realization

1h

### Category

- [ ] Affects Detailed Design

### Requirements / Architecture

- [x] Requirements / Architecture are not affected by this change?