Flatpak: Move configure regeneration out from .yml recipes
Nightly build from the repository regenerates configure as part of each flatpak build, in their. Move that to upper level ./build_flatpak.sh script.
1. It will then run just once. 2. This further unifies nightly .yml with flathub release .yml
Nightly build from the repository regenerates configure as part of each flatpak build, in their. Move that to upper level ./build_flatpak.sh script.
1. It will then run just once.
2. This further unifies nightly .yml with flathub release .yml