Updated publish action

[josephjclark]

A problem with github actions is that if mulitple tags are pushed at once, the "on tag" trigger doesn't work.

This PR attempts to fix that:

• The Dockerize action always looks for the latest worker tag on dockerhub, checks if it exists, and if not, pushes it
• The Publish action calls the Dockerize action

This should (finally) enable better automation of docker builds

Fixes #457

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[josephjclark]

QA to run after merging to main

• If I push a tag, it'll build and deploy, as before
• If I merge to main and auto-tag, it should build and deploy

Kinda hard to test both - I may have to build a fake version

[josephjclark]

So on merging to main, the unpublished docker tag (already on GH but had failed to build earlier) got itself built. Great.

I've just force-pushed the tag again - this should trigger the action but it should not publish the tag as it already exists

EDIT: this is the run but it doesn't look right? https://github.com/OpenFn/kit/actions/runs/23312532255/job/67803325126

Aha - but the tagged branch used the older action. Updating the tag and running against the new action works beautifully https://github.com/OpenFn/kit/actions/runs/23312774565