Update the LFRic apps coupled configuration to use XIOS 2

This is a continuation of https://code.metoffice.gov.uk/trac/lfric_apps/ticket/852

### Are there any linked Issues or Pull Requests?

_No response_

### Brief description

Currently LFRic atmosphere only configurations run with XIOS2.0 (at r2701). The coupled configuration can not run with this version of XIOS, and is currently running with XIOS2.5 (r1873).

It is important to have all configurations running with XIOS2.0 to allow access to the developments as part of NG-Arch WP2 (important for operational models), as well as to allow a platform for update to XIOS3.0.

### Further details of the issue.

**Background investigation**
@timgraham-Met has done some investigations into this issue, and his findings are summarised below:

- At `core2.1` and `apps2.1` he was able to run the full coupled model with XIOS2 by compiling all components **without OpenMP**. NEMO and LFRic core required a small code change to call `xios_oasis_enddef` before `oasis_enddef` to match the XIOS API changes between versions.
- When compiling with OpenMP the model fails. He suspects the failure comes from OASIS.
- From `apps2.2` onwards Tim is unable to compile without OpenMP.