[FEATURE] Publish SNAPSHOT to Maven

[owaiskazi19]

Is your feature request related to a problem?

Plugin should be able to publish artifacts to maven on every PR merged. This requires adding publishing task from OpenSearch in the build.gradle file and also working with @opensearch-project/engineering-effectiveness team to onboard the plugin.

What solution would you like?

1. Add publishing task to build.gradle
2. Create a GHA workflow to publish snapshots to maven on every PR merged.
3. Work with EE team to get the credentials ([release]: Publish opensearch-ai-flow-framework SNAPSHOTs to Maven opensearch-build#4106)

What alternatives have you considered?

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

Do you have any additional context?

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