when I used the file to create CatalogSource, the creation failed and hit error:
[root@preserve-fedora36 cluster-resources]# oc create -f cs-redhat-operator-index-v4-15.yaml 
The CatalogSource "cs-redhat-operator-index-v4-15" is invalid: 
* spec.icon.base64data: Required value
* spec.icon.mediatype: Required value
[root@preserve-fedora36 cluster-resources]# cat cs-redhat-operator-index-v4-15.yaml 
apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  creationTimestamp: null
  name: cs-redhat-operator-index-v4-15
  namespace: openshift-marketplace
spec:
  icon: {}
  image: ec2-3-144-93-237.us-east-2.compute.amazonaws.com:5000/redhat/redhat-operator-index:v4.15
  sourceType: grpc
status: {}

oc-mirror version 
WARNING: This version information is deprecated and will be replaced with the output from --short. Use --output=yaml|json to get the full version.
Client Version: version.Info{Major:"", Minor:"", GitVersion:"4.16.0-202403070215.p0.gc4f8295.assembly.stream.el9-c4f8295", GitCommit:"c4f829512107f7d0f52a057cd429de2030b9b3b3", GitTreeState:"clean", BuildDate:"2024-03-07T03:46:24Z", GoVersion:"go1.21.7 (Red Hat 1.21.7-1.el9) X:strictfipsruntime", Compiler:"gc", Platform:"linux/amd64"}

always

1. Use following imagesetconfigure to mirror to localhost:
cat config.yaml 
kind: ImageSetConfiguration
apiVersion: mirror.openshift.io/v1alpha2
#archiveSize: 8
storageConfig:
  local:
    path: /app1/ocmirror/offline
mirror:
  platform:
    channels:
    - name: stable-4.12                                             
      type: ocp
      minVersion: '4.12.46'
      maxVersion: '4.12.46'
      shortestPath: true
    graph: true
  operators:
  - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.15
    packages:
    - name: advanced-cluster-management                                  
      channels:
      - name: release-2.9             
    - name: compliance-operator
      channels:
      - name: stable
    - name: multicluster-engine
      channels:
      - name: stable-2.4
      - name: stable-2.5
  additionalImages:
  - name: registry.redhat.io/ubi8/ubi:latest                        
  - name: registry.redhat.io/rhel8/support-tools:latest
  - name: registry.access.redhat.com/ubi8/nginx-120:latest
  - name: registry.k8s.io/sig-storage/csi-node-driver-registrar:v2.8.0
  - name: registry.k8s.io/sig-storage/csi-resizer:v1.8.0
`oc-mirror --config config.yaml  file://operatortest --v2`
2. mirror to registry :
`oc-mirror  --config config.yaml --from file://operatortest   docker://ec2-3-144-93-237.us-east-2.compute.amazonaws.com:5000  --v2`

3. Create catalogsource with the created file:
cat cs-redhat-operator-index-v4-15.yaml 
apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  creationTimestamp: null
  name: cs-redhat-operator-index-v4-15
  namespace: openshift-marketplace
spec:
  icon: {}
  image: ec2-3-144-93-237.us-east-2.compute.amazonaws.com:5000/redhat/redhat-operator-index:v4.15
  sourceType: grpc
status: {}

oc create -f cs-redhat-operator-index-v4-15.yaml 
The CatalogSource "cs-redhat-operator-index-v4-15" is invalid: 
* spec.icon.base64data: Required value
* spec.icon.mediatype: Required value

Failed to create catalogsource by the created file.

No error.