Update build image to use golang v1.25.1

[kalleep]

To prepare to use go 1.25.1 for alloy

[jharvey10]

Should we do the windows build image as well?

over at:

tools/build-image/windows/Dockerfile

Looks like it's lagging behind at the moment at 1.24.0

Edit: Actually I'm not sure I understand how (if at all) windows build images are used. I see that dockerfile is used for testing a windows build image, but I wasn't finding any publication of a windows build image. 🤷‍♂️

[kalleep]

Should we do the windows build image as well?

over at:

tools/build-image/windows/Dockerfile

Looks like it's lagging behind at the moment at 1.24.0

Edit: Actually I'm not sure I understand how (if at all) windows build images are used. I see that dockerfile is used for testing a windows build image, but I wasn't finding any publication of a windows build image. 🤷‍♂️

Well windows build image is currently not used at all, but we should bring it back. At the moment everything from that images is included in Dockerfile.windows https://github.com/grafana/alloy/blob/main/Dockerfile.windows#L10-L19. This happened when we migrated to GHA but we should bring it back. Building windows release images takes 1 hour in our ci atm...

[jharvey10]

👍 Okay, I created issue #4584 for that and I'll mark this one as approved in the meantime.