Do not display attestation-manifest and use short sha256 instead of full sha256

[hiifong]

Related: #24973

Before:

After:

Index:

{
  "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"
      }
    }
  ]
}

[silverwind]

Fine with me to omit label style. I guess it depends on how it looks rendered. And maybe we want to reserve the label style for commits only.

[hiifong]

Fine with me to omit label style. I guess it depends on how it looks rendered. And maybe we want to reserve the label style for commits only.

removed label style