mapSource, mapView: Fix handling different attribution logos

We previously never had different attribution logos for
the map sources. Fix this so that it actually works
to update the logo when switching source now that
we use different providers for street and aerial.
1 job for gnome-40 in 6 minutes and 25 seconds (queued for 1 second)
Status Job ID Name Coverage
failed flatpak #1315917


Name Stage Failure
flatpak Test
Uploading artifacts for failed job
Uploading artifacts...
WARNING: gnome-maps-git.flatpak: no matching files
WARNING: repo.tar: no matching files
WARNING: .flatpak-builder/build/gnome-maps/_flatpak_build/meson-logs/meson-log.txt: no matching files
WARNING: .flatpak-builder/build/gnome-maps/_flatpak_build/meson-logs/testlog.txt: no matching files
ERROR: No files to upload
Cleaning up file based variables
ERROR: Job failed: exit code 1