Summary: update to GNOME 48, updated a few translations.

Changed:

• Translation: update French translation (@WedoneOfficiel)
• Translation: update Italian translation (@albanobattistella)
• Translation: update Portuguese translation (@hugok79)
• Translation: update Brazilian Portuguese translation (@johnpetersa19)
• Translation: add 'nl' in LINGUAS (@hugok79)
• Update pypi packages (@MightyCreak)
• Add pre-commit git hooks to run linters (@MightyCreak)
• Docs: improve devs setup structure (@MightyCreak)
• Update to flatpak's GNOME runtime 48 (@MightyCreak)

Fixed:

• Docs: fix incorrect flatpak command to install runtime SDK (@MightyCreak)
• Update GitHub actions: use Ubuntu 24.04, Python 3.9 and new Flatpak image (@MightyCreak)