Do not display `attestation-manifest` and use short sha256 instead of full sha256 (#32851)
Related: #24973
Before:

After:

Index:
```json
{
"schemaVersion": 2,
"mediaType": "application/vnd.oci.image.index.v1+json",
"manifests": [
{
"mediaType": "application/vnd.oci.image.manifest.v1+json",
"digest": "sha256:5967afffdfde104ca1459286a72346baaef8b70ac153325d7a6cd85c7734ac6e",
"size": 672,
"platform": {
"architecture": "amd64",
"os": "linux"
}
},
{
"mediaType": "application/vnd.oci.image.manifest.v1+json",
"digest": "sha256:f9abfcc55320f9ff1f38eeb7dbb4bea10b29c7febfa49ccd7aab9fa02403b9f0",
"size": 672,
"platform": {
"architecture": "arm64",
"os": "linux"
}
},
{
"mediaType": "application/vnd.oci.image.manifest.v1+json",
"digest": "sha256:d70ad19d00c19e40691045cbddc3e8a5a4454c31cc454d1132b13bcaf35b6d46",
"size": 566,
"annotations": {
"vnd.docker.reference.digest": "sha256:5967afffdfde104ca1459286a72346baaef8b70ac153325d7a6cd85c7734ac6e",
"vnd.docker.reference.type": "attestation-manifest"
},
"platform": {
"architecture": "unknown",
"os": "unknown"
}
},
{
"mediaType": "application/vnd.oci.image.manifest.v1+json",
"digest": "sha256:73bc233bf4eac96a404ce3e0430b698831a4ea7050c878d5f76d1d1f133751dd",
"size": 566,
"annotations": {
"vnd.docker.reference.digest": "sha256:f9abfcc55320f9ff1f38eeb7dbb4bea10b29c7febfa49ccd7aab9fa02403b9f0",
"vnd.docker.reference.type": "attestation-manifest"
},
"platform": {
"architecture": "unknown",
"os": "unknown"
}
}
]
}
```
---------
Co-authored-by: silverwind <me@silverwind.io>