gh-1000: Remove conftest imports and consistent pytest.skip

[paddyroddy]

Description

• Sorted conftest imports
• Cleared out benchmarks pytest.skip
• Consistent pytest.skip

Closes: #1000

Refs: #902

Changelog entry

Changed: _generate_grf is now compatible with the Array API

Checks

• Is your code passing linting?
• Is your code passing tests?
• Have you added additional tests (if required)?
• Have you modified/extended the documentation (if required)?
• Have you added a one-liner changelog entry above (if required)?

[paddyroddy]

Test failure is something GHA related

[paddyroddy]

@connoraird, thoughts?

test_generate[numpy-None] (0001_39d6123) - Field 'mean' has failed PercentageRegressionCheck: 29.183546167 > 5.000000000
test_generate[numpy-1] (0001_39d6123) - Field 'mean' has failed PercentageRegressionCheck: 66.193119934 > 5.000000000

[connoraird]

Sorry, I didn't realise this was being done. I have also done this in #979. There is only one difference between the two approaches. I calculate the size of z only once to try to improve performance.

[paddyroddy]

Sorry, I didn't realise this was being done. I have also done this in #979. There is only one difference between the two approaches. I calculate the size of z only once to try to improve performance.

I did say I would move it out of #963 when you reviewed it... There's some other stuff I want in. But that can be done separately.

[connoraird]

Good spots