Adding the latest version of GPCP observations to REF recipes

[hb326]

The precipitation dataset GPCP has a new version (v3.3) available via obs4MIPs and should therefore be updated in the recipes where it is used for the REF.

That means:

• downloading the data from obs4MIPs
• running the recipe(s) with the new observational dataset and check if the results are comparable

[katjaweigel]

I get an error, if I try to use GPCP v3.3:

ValueError: "valid_max" is not of a suitable value (36524220.15025164)
2026-05-13 10:27:43,892 UTC [226022] INFO

Is there already a fix/ branch?

[hb326]

Yes, there is a fix/branch available: ESMValGroup/ESMValCore#3072