Remove `arm/v6` and `v7` from the Docker builds (#1822)
Remove `arm/v6` and `v7` from the Docker builds (#1822)

* added platforms to actions, install libc6-compat for pi

* fix build problem for now. https://github.com/gollum/gollum/runs/6248371141
gollum/gollum,repotag/gollum,repotag/gollum,gollum/gollum,repotag/gollum,gollum/gollum,repotag/gollum,rgroux/gollum,rgroux/gollum,rgroux/gollum,rgroux/gollum,repotag/gollum,rgroux/gollum,gollum/gollum,gollum/gollum