add test for working aeroval diurnal cycle analysis to CI

[jgriesfeller]

the diurnal cycle analysis has just been accidentially removed from main-dev during a bigger than ususal PR. This slipped throuigh testing because there is no test for it.
Because it's a rarely used feature but also a feature that is important when it's needed, we should have a test if it's still working in CI.
Needs hourly model and obs data (example vmrno2 from EBAS and EMEP data from here:
/lustre/storeB/project/fou/kl/CAMS2_40/task4041/EMEP.cams2.40.p2/

The model data needs to be much coarser to be small enough for CI

aeroval option to set: use_diurnal=True

[lewisblake]

One idea is that if it is too big in memory due to hourly data would be to test that this code exists. We could ping it, and mark the test as expecting to fail for no data (or something else)