Replace deprecated Image.NEAREST with Image.Resampling.NEAREST

[llwiggins]

Really tiny change but Image.NEAREST is now deprecated and needs to be replaced with Image.Resampling.NEAREST to run without error. This is already corrected in the upcoming grains refactor but thought it was worth correcting in main in the meantime!

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Before submitting a Pull Request please check the following.

• Existing tests pass.
• Documentation has been updated and builds. Remember to update as required...
  • docs/configuration.md
  • docs/usage.md
  • docs/data_dictionary.md
  • docs/advanced.md and new pages it should link to.
• Pre-commit checks pass.
• New functions/methods have typehints and docstrings.
• New functions/methods have tests which check the intended behaviour is correct.

Optional

topostats/default_config.yaml

If adding options to topostats/default_config.yaml please ensure.

• There is a comment adjacent to the option explaining what it is and the valid values.
• A check is made in topostats/validation.py to ensure entries are valid.
• Add the option to the relevant sub-parser in topostats/entry_point.py.

[ns-rse]

All looks good, thanks @llwiggins for fixing this.