cf1.11 checker plugin flags CF 7.1 "Bounds variable lev_bnds and parent variable lev have the following matching attributes"

The following cf convention recommendation is flagged. Check to see if we can do anything about this or if we have to add it to the ignore list.

```
{
"mip_table": "atmos@day",
"checker": "cdds_cf:1.11",
"error_message": "\u00a77.1 Cell Boundaries: Bounds variable lev_bnds and parent variable lev have the following matching attributes ['standard_name', 'units']. It is recommended that only the parent variable of the bounds variable contains these attributes",
"affected_files": 6,
"affected_vars": "cl_tavg-al-hxy-u"
},
```

Start by reproducing the cdds_cf:1.11 checker result for the atmos@day table and affected variable cl_tavg-al-hxy-u, then inspect how matching bounds attributes are handled. Done means deciding whether the recommendation is valid for these outputs and documenting or implementing either a checker change or an ignore-list entry.

Written by the indexing model from the issue text.