Patch: Pandas 3.x Compatibility

[RHammond2]

Fix Data Type Issues To Enable Pandas 3.x Compatibility

This PR fixes various issues relating to how data are accessed in Pandas DataFrames, changes to default datetime resolutions, and a previously unidentified metrics bug.

PR Checklist

• CHANGELOG.md has been updated to describe the changes made in this PR
• Documentation
  • Docstrings are up-to-date
  • Related docs/ files are up-to-date, or added when necessary
  • Documentation has been rebuilt successfully
  • Examples have been updated
• Tests pass (If not, and this is expected, please elaborate in the tests section)
• PR description thoroughly describes the new feature, bug fix, etc.

Related issues

N/A

Impacted areas of the software

• wombat/core/library.py
  • format_weather: Manually casts datetime data to "ns" resolution for updated Pandas compatibility.
• wombat/core/post_processor.py
  • Metrics._apply_inflation_rate: Converts all cost columns to float types for Pands 3.x incompatibility with implicit casting during mathematical operations.
  • Metrics.vessel_crew_hours_at_sea: Replaces group_cols with frequency.group_cols for total_hours grouping that was previously missed.
• wombat/windfarm/windfarm.py
  • Windfarm._create_graph_layout: Repalces .values with .to_numpy() for turbine, substation, and electrolyzer id creation.

Additional supporting information

Python version: 3.13.11
WOMBAT version (wombat.__version__): 0.13.2

Test results, if applicable

Tests now pass with Pandas 2.x and 3.x