Added iris-grib depedency

[schlunma]

Description

This PR adds the iris-grib dependency in order to update the docker container to get successful tests for #2178 (following this comment).

Related to #2178

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.62%. Comparing base (ee16a95) to head (46570ec).
Report is 32 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2453   +/-   ##
=======================================
  Coverage   94.62%   94.62%           
=======================================
  Files         246      246           
  Lines       14055    14055           
=======================================
  Hits        13299    13299           
  Misses        756      756           

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