Performance Shift(s): 684cd2de

[github-actions]

Benchmark comparison has identified performance shifts at

• commit 684cd2d (Cubelist contain only cubes -- resurrected #4767).

Please review the report below and take corrective/congratulatory action as appropriate 🙂

Performance shift report

       before           after         ratio
     [49a510b3]       [684cd2de]
     <main~1>         <main>    
+      2.11328125         2.859375     1.35  experimental.ugrid.regions_combine.CombineRegionsCreateCube.track_addedmem_create_combined_cube(500)

Generated by GHA run 2399147770

[pp-mo]

Unlike timings, these 'addedmem' tests can probably be compared with subsequent runs.
Latest at https://github.com/SciTools/iris/actions/runs/2411695692 shows this test measuring ~3.0Mb both before + after that commit (i.e. difference is insignificant + benchmark passes).
So I think that shows this up as not being significant.