ci: GH workflow for publishing docker images

[bermuell]

Description

Closes: #1592
GH workflow to publish ICS docker images

Workflow is triggerd to build

• interchain-security:latest image when a commit is pushed to 'main' branch
• interchain-security:vX.Y.Z when a tag with pattern vX.Y.Z is pushed
• interchain-security:vX.Y.Z-lsm when a tag with pattern vX.Y.Z-lsm is pushed

for all other commits/tags no docker image workflow will be triggered

---

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• Included the correct type prefix in the PR title
• Targeted the correct branch (see PR Targeting)
• Provided a link to the relevant issue or specification
• Reviewed "Files changed" and left comments if necessary
• Confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• Confirmed the correct type prefix in the PR title
• Confirmed all author checklist items have been addressed
• Confirmed that this PR does not change production code

[p-offtermatt]

Looks reasonable to me.
Unfortunately, iirc the only realistic way to test this is to merge and
check what it publishes. An alternative might be forking the repo to informalsystems and playing with it there (at least we don't mess with the real repo)

wdyt?

[bermuell]

Looks reasonable to me. Unfortunately, iirc the only realistic way to test this is to merge and check what it publishes. An alternative might be forking the repo to informalsystems and playing with it there (at least we don't mess with the real repo)

wdyt?

yes you're right. did not find a way to test this outside the PR. will observe what is published and adapt if needed.

[p-offtermatt]

Workflow looks good as far as I can tell, so approval and let's see whether it works as expected.

[MSalopek]

Added some comments.

Let's reduce the amount of images being pushed. The most important events happen on push to main and when a tag/release is created.

[MSalopek]

Thanks for the changes!

LGTM.