chore(layers): add workflows for govcloud layers

[am29d]

Summary

Changes

Please provide a summary of what's being changed

This PR adds two workflows to publish layers to govcloud. The documentation update will come in a separate PR.

Please add the issue number below, if no issue is present the PR might get blocked and not be reviewed

Issue number: closes #3423

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[dreamorosi]

Added two comments, one about docs and another about a missing permission.

I don't have a lot of context on what the workflow is supposed to do, and I haven't tested it so I assume the secrets and permissions needed by the workflows are already (or will be) in place.

Besides that, if possible, please update the sections here to make sure it's clear at which point of the release we need to run these workflows.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[am29d]

Added the workflow trigger to the layer deployment pipeline and updated the maintainers doc diagram. The deployment numbers are estimated, I will change them once it has been deployed.

We still need to add readonly env for the prod, I don't want to pass write IAM to readonly workflow, @sthulb .

Before the next release we need to deploy and bump the versions once, like we do for new region deployments.

[dreamorosi]

Thank you both, if possible let's test the workflows in beta right after merging

Already approved offline