Publish arm64 woodpecker-server

[relnod]

Clear and concise description of the problem

I want to run the woodpecker-server docker image on an arm64 computer. On https://hub.docker.com/r/woodpeckerci/woodpecker-server/tags I can only find linux/amd64 builds.

Suggested solution

Adding platforms setting to the docker ci might be enough.

Alternative

No response

Additional context

No response

Validations

• [X] Read the Contributing Guidelines.
• [X] Read the docs.
• [X] Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[anbraten]

in progress see #635