ESM1.6 now has a new development "AMIP" configuration, and a similar configuration will soon be added for ESM1.5. These configurations use only the atmosphere model, reading in data files in place of the ocean and sea-ice models.

A few of the qa tests fail with these configurations - see here for an example. I think we'll need some small adjustments to the following tests:

1. test_config_start:
   The AMIP configurations start on 1978-01-01. I think we could add a branch.config_scenario == "amip" option to this test with the 1978 start date.

2. test_cice_configuration_icefields_nml_in_ice_history_nml

   This checks that the CICE namelists are correctly put together. We'll want to skip this test for the AMIP configurations as there's no CICE sub-model.

We can leave the failing restart frequency tests as is. Payu can now do date based restart pruning with just the UM, and so for these I just need to update the configurations rather than the tests.