Tests fail if apk plugin already installed

[pabloyoyoista]

Testing locally seems to only be possible when the apk plugin is not already installed. When it is installed, the plugin loader loads both the local "dev" plugin and the plugin from the system directory (since we need to fetch upstream plugins like appstream from that directory). Therefore, each requested action is executed twice (once by each apk plugin) and tests have unexpected behavior. Current workaround I found is to remove the plugin from the system directory while doing the testing and then reinstall it.

This is an upstream issue and it is best solved discussing with upstream, but I want to document it here so I don't waste another morning in the future trying to figure out an already-known issue :)