Add to downstream ci (#351)

[codecov-commenter]

Codecov Report

Patch coverage has no change and project coverage change: -42.07% :warning:

Comparison is base (ce74335) 95.99% compared to head (d82872b) 53.93%.

:exclamation: Current head d82872b differs from pull request most recent head 9ea4f6e. Consider uploading reports for the commit 9ea4f6e to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #352 +/- ## =========================================== - Coverage 95.99% 53.93% -42.07% =========================================== Files 26 26 Lines 2073 2073 Branches 231 231 =========================================== - Hits 1990 1118 -872 - Misses 54 937 +883 + Partials 29 18 -11 ``` [see 19 files with indirect coverage changes](https://app.codecov.io/gh/ecmwf/cfgrib/pull/352/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ecmwf)

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[FussyDuck]

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