Tested update with the following command:

guix refresh -l python-importlib-metadata | tr ' ' '\n' | grep '@' | xargs ./pre-inst-env guix build --keep-going --check

Most dependents build fine, there are some more to be fixed.

```
guix build: error: build of `/gnu/store/23zz3gkbcp7rhngx5kqqkifgllnnn87d-orange-3.31.1.drv', `/gnu/store/8g57fz279rsfbp7ygyfdkkigxz6alsd9-python-dolfin-adjoint-2019.1.0.drv', `/gnu/store/hpp2hysd3rjwy9kzbfrip1mjsp7cw42x-jrnl-1.9.7.drv', `/gnu/store/im8523db69cn0zn8d6357fljvnj9h51v-python-pytest-virtualenv-1.7.0.drv', `/gnu/store/jb7dhh6qyl1ywfl560g2fdincqln0j0m-python-behave-web-api-1.0.6.drv', `/gnu/store/k0yar63qm2h4kv8qbl0dbp04c6lvm8kz-python-pysnptools-0.4.11.drv', `/gnu/store/nr9isakhk3bxkl6p5v65gvqahy4n5fmy-dosage-2.17.drv', `/gnu/store/pf79l2hn6brzwl0b1q0bynlh42501s3v-electrum-4.1.5.drv', `/gnu/store/pvnxfjfr9fg0ap8lwia60vs53rgdclrh-gr-satellites-4.2.0.drv', `/gnu/store/qg7mfxcn2ayyq4v4lc1bkxddayfj54bp-gnss-sdr-0.0.15.drv', `/gnu/store/qgc7prgchmwn9hyy36hsn12cyraixvcf-electron-cash-4.2.6.drv', `/gnu/store/sc72sngxh0fbklbn66hly6k6r7zy6fcl-gqrx-2.15.8.drv', `/gnu/store/ympmpv7ci9xav22jaisq9kwrp1qq8w00-onionshare-2.4.drv' failed
```