fix: end_ensemble_manager check allocated variables are allocated bef…

[hkershaw-brown]

Description:

This pull request adds a check in end_ensemble_manager to only call deallocate on arrays that have been allocated.

The allocatable variables in the type are:

integer, allocatable :: my_copies(:)
integer(i8), allocatable :: my_vars(:)
real(r8), allocatable :: copies(:, :)
real(r8), allocatable :: vars(:, :)
type(time_type), allocatable :: time(:)
integer, allocatable :: task_to_pe_list(:),
pe_to_task_list(:)

Fixes issue

fixes #1174

Note 1174 could be fixed by checking for num_obs_in_set = 0 and if so not ending fwd_op and qc ensemble handles, but I think the more general solution of checking if the arrays are allocated before deallocating in end_ensemble_manager. Because end_ensemble_manager is a cleanup routine so maybe you are bailing early, failing, or you have not realized perfect_model_obs can bail early - I don't think enforcing (by runtime error) a matching init/end for ensemble_manager is that helpful.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Documentation changes needed?

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.

Tests

Please describe any tests you ran to verify your changes.

Checklist for merging

• Updated changelog entry
• Documentation updated
• Update conf.py

Checklist for release

• Merge into main
• Create release from the main branch with appropriate tag
• Delete feature-branch

Testing Datasets

• Dataset needed for testing available upon request
• Dataset download instructions included
• No dataset needed

[mjs2369]

Clean fix, I agree this is the better route over a check on num_obs_in_set