add NEP18 overrides for max, min, and round

[keewis]

numpy recently changed the names of amin and amax to min and max, with the old names being kept around as aliases. However, that means that we need to override both until numpy<1.25 drops out of support (which will be a while, considering that numpy=1.25 has not been released yet).

Additionally, round_ has been deprecated in favor of round.

The test coverage has already been sufficient (we didn't get errors in CI because we don't test numpy dev), but I changed the round tests to not use the deprecated name.

• Executed pre-commit run --all-files with no errors
• The change is fully covered by automated unit tests
• Documented in docs/ as appropriate

[jules-ch]

Thanks