Fix publish_tool ci

[ponkio-o]

What this PR does: I forgot to fix the CI where docker push is executed 😅

Why we need it: To publish linux/arm64 images

Which issue(s) this PR fixes:

related: #5395

Does this PR introduce a user-facing change?: No

[ponkio-o]

In my assumption, when this PR is merged into the master branch, a container image compatible with linux/arm64 will be published on ghcr. After that, I plan to change the base image and make various container images compatible with arm64.

[Warashi]

LGTM. Thank you.

[ponkio-o]

👍

$ docker manifest inspect ghcr.io/pipe-cd/piped-base:v0.50.0-22-ge276b89
{
   "schemaVersion": 2,
   "mediaType": "application/vnd.oci.image.index.v1+json",
   "manifests": [
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 673,
         "digest": "sha256:049d563d3e89e19d2d6465f0ab9aa923b9dd448b5172698e3488b0d367cdcfb6",
         "platform": {
            "architecture": "amd64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 673,
         "digest": "sha256:2d8b7e1ad6da1ef34df28548dade7af28b3b25f5b97c30b3b645aa9e50ba86e5",
         "platform": {
            "architecture": "arm64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 566,
         "digest": "sha256:3d3387cef4f26c719a0376be86d4320c46fb137d1f41ac60b539be3f79e20bc2",
         "platform": {
            "architecture": "unknown",
            "os": "unknown"
         }
      },
      {
         "mediaType": "application/vnd.oci.image.manifest.v1+json",
         "size": 566,
         "digest": "sha256:23e7bc9c3ff826977b382a488c58b14e46ef2c8f305521cc5ed62fbb31feb8bc",
         "platform": {
            "architecture": "unknown",
            "os": "unknown"
         }
      }
   ]
}