Remove RPMs and base image references from the manifest-all.txt file

https://github.com/redhat-developer/devspaces/blob/devspaces-3-rhel-8/product/manifest/3.0.0/manifest-all.txt contains refs to base images and rpms, which are now handled by Freshmaker and don't need to be processed by Incident Response / PS / PSSC.

Based on conversation today with rhn-support-scorneli, we can remove those entries into a separate file, and no longer get JIRAs created for CVEs related to RPM updates.