The registry path is lower case, so it can be different from `FDO_UPSTREAM_REPO`
Found on the GNOME gitlab:
For projects like mutter,
FDO_UPSTREAM_REPO is set to
However, the registry url is for example
The templates should lower case the
FDO_UPSTREAM_REPO upstream repo so
skopeo doesn't get lost.
We still need to keep
FDO_UPSTREAM_REPO untouched, because we embed this as a label in the created image, so changing it there might have undesirable side effects.