Add automation to build and publishing build artifacts for release

[deepdatta]

Is your feature request related to a problem? Please describe.
Currently we need 2 MCMs one for creating the Gemfile and publish it to rubygems.org and another for creating a Logstash-oss-with-opensearch-output-plugin docker image and publish it to the Docker registry and also create a tar of the image.

Describe the solution you'd like
It would be great to have a GitHub action to do the build steps to create the Gemfile and Docker image tar and push it to an internal repo. Then we can have a shorter manual step to publish the artifacts to rubygems.org and Docker registry

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[sastorsl]

Can you describe how the docker build process has been handled before?

I would for one really like to see automated builds following upstream logstash with the plugin.

[dlvenable]

@sastorsl , We currently use an internal process for releasing this plugins. This process has various checks for quality control and to ensure correctness.

One goal of this current request is to automate the process. Another is to make it more open by using GitHub Actions, the opensearch-build, or some combination of the two to perform builds.

I hope that answers your question.

[sastorsl]

Some variation over dependabot could perhaps be of help?

[dblock]

Related to #230.