fix: use GitHub Pages helm repo and correct chart name for OAI 5G Core
- Change HelmRepository from OCI to default (GitHub Pages)
- Change HelmRelease chart name from oai-5g-basic to oai-5g-core
Closes: OSM-XXXX
Signed-off-by:
sanchezal <alejandro.sanchezgutierrez.ext@telefonica.com>