Adds support for building python 3.12-minimal container for RHEL10.

To multispec.yaml is added section about rhel10 and
build it 3.12-minimal on RHEL10

manifest-minimal.yml is updated to add Dockerfile.rhel10

base image is ubi10-minimal:latest

Signed-off-by: Petr "Stone" Hracek <phracek@redhat.com>