Add in docker/metadata action's annotations and labels

[halkeye]

Tools like renovate or dependbot use the standard opencontainer labels to know where sourcecode is located, and in the case of releases and tags being used, generate changelogs inside of prs

I think i managed to connect docker/metadata which takes care of setting up all the labels for you, to the ci process that builds the docker image, so it should always be up to date and accurate

I also added support for forks to build their own image on github (so i could do testing), i can revert that if desired.

[halkeye]

I really wanted to wait for https://github.com/halkeye/docker-postgres-backup-local/actions/runs/18184122590/job/51765284575 to finish and be a success before submitting the PR, but its a long build process and i didn't want to forget it.

[halkeye]

confirmed via

regctl image config --format '{{ jsonPretty .Config.Labels }}' ghcr.io/halkeye/docker-postgres-backup-local:18-alpine

{
  "org.opencontainers.image.created": "2025-10-02T07:12:36.689Z",
  "org.opencontainers.image.description": "Backup PostgresSQL to local filesystem with periodic backups and rotate backups.",
  "org.opencontainers.image.licenses": "MIT",
  "org.opencontainers.image.revision": "eb82d9df44105a51d92096630d2892fbce6ff669",
  "org.opencontainers.image.source": "https://github.com/halkeye/docker-postgres-backup-local",
  "org.opencontainers.image.title": "docker-postgres-backup-local",
  "org.opencontainers.image.url": "https://github.com/halkeye/docker-postgres-backup-local",
  "org.opencontainers.image.version": "main"
}

[halkeye]

I split them up so I could do faster iteration of testing by just building alpine instead of default
lemme know if you want me to put it back

[halkeye]

if you are feeling up for it (because it is october), and you want to merge it, can you throw a hacktoberfest-accepted