ReFrame tests for compat layer are broken due to using test parameters in class body

The worst part is that ReFrame just ignores the "syntax error", and then concludes with success (because all zero tests have passed)...

eessi@ip-172-31-18-112 ~/compatibility-layer $ reframe -r -v -c ./test/compat_layer.py
[ReFrame Setup]
  version:           3.9.1
  command:           '/cvmfs/pilot.eessi-hpc.org/2021.12/compat/linux/x86_64/usr/lib/python-exec/python3.9/reframe -r -v -c ./test/compat_layer.py'
  launched by:       ec2-user@ip-172-31-18-112.eu-west-1.compute.internal
  working directory: '/home/ec2-user/compatibility-layer'
  settings file:     '<builtin>'
  check search path: '/home/ec2-user/compatibility-layer/test/compat_layer.py'
  stage directory:   '/home/ec2-user/compatibility-layer/stage'
  output directory:  '/home/ec2-user/compatibility-layer/output'

/cvmfs/pilot.eessi-hpc.org/2021.12/compat/linux/x86_64/usr/lib/python-exec/python3.9/reframe: skipping test file '/home/ec2-user/compatibility-layer/test/compat_layer.py': reframe syntax error: accessing a test parameter from the class body is disallowed (rerun with '-v' for more information)
Traceback (most recent call last):
  File "/cvmfs/pilot.eessi-hpc.org/2021.12/compat/linux/x86_64/usr/lib/python3.9/site-packages/reframe/frontend/loader.py", line 237, in load_from_file
    util.import_module_from_file(filename, force)
  File "/cvmfs/pilot.eessi-hpc.org/2021.12/compat/linux/x86_64/usr/lib/python3.9/site-packages/reframe/utility/__init__.py", line 91, in import_module_from_file
    return _do_import_module_from_file(filename, module_name)
  File "/cvmfs/pilot.eessi-hpc.org/2021.12/compat/linux/x86_64/usr/lib/python3.9/site-packages/reframe/utility/__init__.py", line 68, in _do_import_module_from_file
    spec.loader.exec_module(module)
  File "<frozen importlib._bootstrap_external>", line 850, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "/home/ec2-user/compatibility-layer/test/compat_layer.py", line 11, in <module>
    class RunInGentooPrefixTest(rfm.RunOnlyRegressionTest):
  File "/home/ec2-user/compatibility-layer/test/compat_layer.py", line 17, in RunInGentooPrefixTest
    if eessi_version != '2021.06':
  File "/cvmfs/pilot.eessi-hpc.org/2021.12/compat/linux/x86_64/usr/lib/python3.9/site-packages/reframe/core/meta.py", line 143, in __getitem__
    raise ReframeSyntaxError(
reframe.core.exceptions.ReframeSyntaxError: accessing a test parameter from the class body is disallowed

Loaded 0 test(s)
Generated 0 test case(s)
Filtering test cases(s) by name: 0 remaining
Filtering test cases(s) by tags: 0 remaining
Filtering test cases(s) by other attributes: 0 remaining
Final number of test cases: 0
[==========] Running 0 check(s)
[==========] Started on Tue Nov 30 07:52:29 2021

[----------] waiting for spawned checks to finish
[----------] all spawned checks have finished

[  PASSED  ] Ran 0/0 test case(s) from 0 check(s) (0 failure(s), 0 skipped)
[==========] Finished on Tue Nov 30 07:52:29 2021
Run report saved in '/home/ec2-user/.reframe/reports/run-report.json'
Log file(s) saved in '/tmp/rfm-m33a1fsh.log'

EESSI / compatibility-layer

ReFrame tests for compat layer are broken due to using test parameters in class body #145