Run `pwa-metainfo-generator.py` in CI

[castrojo]

Ok so I tried to follow these instructions:

• https://gitlab.gnome.org/mwleeds/gnome-pwa-list/

My intent was to PR a ublue-pwa.xml file here so we could ship PWAs people want, like Gmail, etc. But I got stuck on figuring out the python dependencies so while I fix that I wanted to jot this down and I think @bketelsen might be interested in working on this.

Here's what a PWA line in the csv looks like:

https://mail.google.com/,LicenseRef-proprietary,Office,social-info=intense,adaptive,"Google Mail"

We then run the pwa-metainfo-generator.py on the csv and then commit the xml right in the repo after merge and then it just ships with the images consuming the package.

Maybe pwa-metainfo-generator.py should be run as a github action and we should run it out of here and then push those out to the images. For the following reasons:

• The csv file is relatively simple, I can PR the webapp I need and then it'll just come in the next update and will show up in the store.
• We don't want to run a PWA app store, so we'll put things in here that we feel people need, the mainstream stuff like Office, Gmail, the kind of thing that people need to be able to do their jobs.
• But since it's a consumable action, someone can use this action from their custom build to ship whatever they want. That means startingpoint can let the user declare their system packages, flatpaks, and now PWAs!
• Since it's community driven we'll end up with curated sets of PWAs instead of a bunch of spammy webapps that litter all those pwa index sites.
• It'd be nice if we could integrate with yafti so people can ship PWAs right ootb. cc @marcoceppi

Or if upstream wants us to just start adding apps to that git repo and then we just ingest it and then that ends up on the image that'd be great too!

[castrojo]

The PWA functionality isn't where it needs to be, so let's punt this unless someone really wants to do it.