devtool needs to support new repo URL

devtool currently has the cm and psu-shared helm repos set to https://registry.psu.edu/chartrepo/shared, but the new URL for future helm chart versions is oci://ghcr.io/psu-pennstateit-swe/charts.

We need to support the new URL and figure out a reasonable transition for how the existing project specific .devtool.config files should interact with the repo change. At this point, old charts are still in registry.psu.edu but new ones will be in ghcr.io.