Fix incorrect unit conversion in hydro function in convert.py

[lukasschirren]

Removed unnecessary factor of 1000/24 from the runoff calculation, as pointed out by user JKALanger. The function now correctly calculates runoff in m3 per hour by directly multiplying the depth (in meters per hour) by the basin area (in square meters).

Closes # (if applicable).

Changes proposed in this Pull Request

Checklist

• Code changes are sufficiently documented; i.e. new functions contain docstrings and further explanations may be given in doc.
• Unit tests for new features were added (if applicable).
• Newly introduced dependencies are added to environment.yaml, environment_docs.yaml and setup.py (if applicable).
• A note for the release notes doc/release_notes.rst of the upcoming release is included.
• I consent to the release of this PR's code under the MIT license.