[`build-images`] Authenticate in both org default registries

[alambike]

Motivation

We have 2 inputs for the default org registries:

firestarter-workflows/firestarter/workflows/build_images/build_images.py

Lines 44 to 45 in 0976025

	self._snapshots_registry = self.vars.get('snapshots_registry')
	self._releases_registry = self.vars.get('releases_registry')

But we only authenticate in the corresponding type registry, depending on whether we are building snapshots or releases:

firestarter-workflows/firestarter/workflows/build_images/build_images.py

Lines 169 to 176 in 0976025

	default_registry = getattr(self, f"{self.type}_registry")
	default_registry_creds = getattr(self, f"{self.type}_registry_creds")
	if self.login_required:
	self.login(
	self.auth_strategy,
	default_registry,
	default_registry_creds,

We want to log in both registries to avoid issues building images that depends on other base images (Dockerfile FROM XXX) that can be located in any of the org default registries.