CI: CUDA tests

[casperdcl]

Describe your changes

before	this PR	follow-up PRs
conda	conda	- (move to conda-forge, halve our CI times)
-	test(py3.8,np1.21/py3.10,np1.24)	test(pyX.X,npX.X,mac/win/nix)
- (jenkins)	test-cuda	test-cuda(pyX.X,npX.X)

• add some filters so test-cuda only runs GPU (not CPU) tests (brings down test time from ~15 min to ~2min)
• adds TESTS_FORCE_GPU to fix CI: unskip expected tests #1731
• update README.md
• update .github/workflows/README.md

Describe any testing you have performed

see CI

Link relevant issues

part of #1598
fixes #1731
closes #1640

Checklist when you are ready to request a review

• I have performed a self-review of my code
• I have added docstrings in line with the guidance in the developer guide
• I have updated the relevant documentation
• I have implemented unit tests that cover any new or modified functionality
• CHANGELOG.md has been updated with any functionality change
• Request review from all relevant developers
• Change pull request label to 'Waiting for review'

Contribution Notes

Please read and adhere to the developer guide and local patterns and conventions.

• The content of this Pull Request (the Contribution) is intentionally submitted for inclusion in CIL (the Work) under the terms and conditions of the Apache-2.0 License.
• I confirm that the contribution does not violate any intellectual property rights of third parties

[casperdcl]

btw bizarre docker failure:

======================================================================
FAIL: test_Function (test_functions.TestFunction)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/CIL/Wrappers/Python/test/test_functions.py", line 93, in test_Function
    self.assertEqual(a2, g(d))
AssertionError: 1.0496462747793063 != 1.0496462747793065

caused by the last commit:

- - libgcc-ng
- - libstdcxx-ng
+ - libgcc-ng     # [linux]
+ - libstdcxx-ng  # [linux]
+ - _openmp_mutex # [linux]

... any ideas?

[MargaretDuff]

btw bizarre docker failure

If you change it to self.assertAlmostEqual it will pass 😃 Not sure why it failed though

[gfardell]

I only spotted one area where the tests have both tigre and astra tests. There may also be some tests that are astra-cpu only so I think these will be caught to - in practise a few extra tests probably don't matter though.

Please could you document the style and keywords in the contribution guide so we can make sure future unit-tests conform.

[casperdcl]

document the style and keywords in the contribution guide so we can make sure future unit-tests conform

it's a complete unacceptable mess with no consistent style nor keywords to conform to 😅. Definitely worth opening a separate issue.

[casperdcl]

@gfardell any objections to this file?

[gfardell]

no objections!

[casperdcl]

ok, though I presume Windows users will have to manually remove the # [linux] lines...

[gfardell]

btw bizarre docker failure:

======================================================================
FAIL: test_Function (test_functions.TestFunction)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/CIL/Wrappers/Python/test/test_functions.py", line 93, in test_Function
    self.assertEqual(a2, g(d))
AssertionError: 1.0496462747793063 != 1.0496462747793065

caused by the last commit:

- - libgcc-ng
- - libstdcxx-ng
+ - libgcc-ng     # [linux]
+ - libstdcxx-ng  # [linux]
+ - _openmp_mutex # [linux]

... any ideas?

Just floating point precision. It's a bad test!