Update conda version

[0ctagon]

The conda build fails because plothist_utils is not yet in conda (see conda-forge/plothist-feedstock#5)
It's currently being reviewed conda-forge/staged-recipes#31524, and when this will be accepted, we can update the conda version.

[0ctagon]

Done 😄
plothist_utils-feedstock: https://github.com/conda-forge/plothist_utils-feedstock
latest version on conda-forge: conda-forge/plothist-feedstock#8

[cyrraz]

Hi @0ctagon, I reopened this issue now that plothist_utils was renamed plothist-utils.