Container Action that I published builds again when I call it?

[mhemken-vts]

The setup

I followed the instructions for building a Docker Container Action. I successfully built an image and published it to ghcr.io/<my-user>/<my-repo>:release.

The problem

Why does this action re-build a container image when it can simply pull it and run it?

When I call this action, it doesn't run what I expect. It first builds the Dockerfile and then it runs the container. This is unexpected because I have already built the container and published it to ghcr.io. Why is this happening?

Here's my workflow

name: The Proof
run-name: the-proof
"on":
  push:
    branches:
      - main
jobs:
  proof:
    runs-on: ubuntu-latest
    steps:
      - name: Run the hello world
        uses: <my-user>/<my-repo>@release

Here's the action.yml

name: 'my-action-name'
author: 'me'
description: 'A GitHub Action to print hello world'
runs:
  using: 'docker'
  image: 'docker://ghcr.io/<my-user>/<my-repo>:release'
branding:
  icon: 'check-square'
  color: 'white'

Additional info

I'm running a go program that simply prints hello world. It runs correctly and I see the output in the action logs. But it doesn't make sense that it needs to run docker build! I've alredy built the image!

[mhemken-vts]

I also used https://github.com/github/issue-metrics/tree/main as an example for a container action. I doubt users of this action are required to rebuild the image each time the use this. Or do they?

[mhemken-vts]

I've managed to get this working... but I'm not exactly sure why.

And by "working" I mean it does a Pull instead of a Build (but the Pull is unauthorized).