container/build.sh: FROM_IMAGE=rockylinux-10 default for >=tentacle
We build centos9 and rocky10 packages and containers by default now for wip, main, and tentacle branches as of https://github.com/ceph/ceph-build/pull/2557.
Starting with tentacle, we want a `podman pull quay.ceph.io/ceph-ci/ceph:tentacle` or `podman pull quay.ceph.io/ceph-ci/ceph:$SHA1` to get the container with Rocky 10 as the Base OS image, or FROM_IMAGE.
Fixes: https://tracker.ceph.com/issues/75673 Signed-off-by: David Galloway <david.galloway@ibm.com>