Prepare GitHub Actions pipeline for internal build for OBF, OPF, OPFF

[teolemon]

What

The plan would be to release Internal versions to motivate us and to enable us to make the app modular in an iterative fashion

### Tasks
- [ ] Prepare GitHub Actions pipeline for internal builds for Open Beauty Facts
- [ ] Prepare GitHub Actions pipeline for internal builds for Open Products Facts
- [ ] Prepare GitHub Actions pipeline for internal builds for Open Pet Food Facts
- [ ] Ensure all the keys are accessible from the repository (not all apps are signed with the same key

Why

• This will enable us to make the app modular in an iterative fashion

Part of

• https://github.com/openfoodfacts/smooth-app/issues/4093

[monsieurtanuki]

Just curious: nothing for runners?

[M123-dev]

Open Supplements Facts

[teolemon]

We put them in Open Products Facts historically, but many of them are still in Open Food Facts

[monsieurtanuki]

Maybe that would be something to think about for the 1-million-user goal: the flexibility to create almost on demand a new "Open name-a-niche Facts". Because some people can get passionate about their niches, rather than "random" products.

[M123-dev]

Good news. The build system we have here so so modular it shouldn't take long to update it to any store listing

[teolemon]

@M123-dev @monsieurtanuki I have committed a lot of Open Beauty/Pet Food/Products logo assets yesterday: https://github.com/openfoodfacts/openfoodfacts-server/pull/8459