_Ideally_, we would just want to export it as ECMAscript module.

For now, to support both, we can use a shared JSON file.

It would be nice to use the `import cfg from "./config.js" assert { "json" };` but
that is experimental.

Re-use `@semantic-release/config-gitlab-npm`

The CI does this by default now.

This should be done by default in the GitLab runner setup.

We can remove this once the runners do it.

Makes job dependencies explicit so the CI can optimise throughput.

The new license is not a markdown file, so the symlink filename was
incorrect.

The package needs to be set to private, as we aren't members of
@semantic-release, and so can't publish this to NPM.
The licence and repository URL were also out of date, and have now
been updated.

As `config-gitlab-npm` isn't currently published, we need to
manually include this config for now.

K8s runners aren't currently available for this project, so EC2
will be used for now.

Any parts of `ci/templates` that were in use have been replaced by
local definitions. This was done by reusing the
`semantic-release/dockerode-tag` CI setup.