OCI chart release

[joryirving]

Update the release pipeline to continue to push to the ghcr helm repository, as well as push an OCI image and sign it.

This also cleans up the chart.version reference using a template.
This publishes the objects as ghcr.io/itzg/minecraft-server-charts/<chartname>

Successful run: https://github.com/joryirving/minecraft-server-charts/actions/runs/13891040259/job/38862979875

OCI artifact for mc-router: https://github.com/joryirving/minecraft-server-charts/pkgs/container/minecraft-server-charts%2Fmc-router
OCI artifact for minecraft: https://github.com/joryirving/minecraft-server-charts/pkgs/container/minecraft-server-charts%2Fminecraft

I've tested it successfully in my own cluster, and the changes to chart-version work.

Unfortunately, I couldn't get cosign working:
https://github.com/joryirving/minecraft-server-charts/actions/runs/13890798966/job/38862394740#step:11:21

Closes #254

[itzg]

Thanks! This is ready to merge...and do its thing? If so, I'll merge it.

[itzg]

Thanks. This makes me realize I need dependabot enabled on this repo.

[joryirving]

It should be ready to roll! The only validation I wasn't sure on, is if you wanted the charts bumped to a different version.

I'm currently running mc-router and minecraft charts built using this in my own repo, successfully.

[itzg]

The only validation I wasn't sure on, is if you wanted the charts bumped to a different version.

Like a patch version bump instead of minor? I was fine with either.

[joryirving]

Great! Then it should be good to go.

[itzg]

How does that build look:

https://github.com/itzg/minecraft-server-charts/actions/runs/13981301196/job/39146916051

[joryirving]

Looks good to me! The only thing is that it's based on your previous helm release chart logic, so it will only publish when the version is bumped, so only 2/5 are published right now. I'm not sure if you want to do a dummy bump for the rest of the charts.

[itzg]

Yeah, I inherited all that chart version release behavior from when the repo got migrated into my github org.

I'll bump those chart versions to get the release going.