Adopt minor release branches for patch releases

[Boomatang]

Summary

Adopt long-lived minor release branches (e.g., authorino-1.0, authorino-1.1) for managing patch releases within the same minor version.

Context

As part of the Kuadrant standardization effort, all repositories are adopting minor release branches to provide:

• Better backporting capabilities for CVE fixes and patches
• Clearer release tracking
• Consistent submodule reference strategies across product-build repos

Currently, authorino only has a main branch, which makes it difficult for downstream product builds to track specific release versions.

Proposed Solution

1. Create release branches following the pattern authorino-X.Y for each minor version
2. Tag releases from these branches (e.g., v1.0.0, v1.0.1 from authorino-1.0)
3. Document the branching strategy in RELEASE.md or CONTRIBUTING.md

Acceptance Criteria

• Release branch pattern documented
• At least one minor release branch created for the current stable version
• Downstream product-build can track the release branch instead of main

Related: Kuadrant/sector#2, Kuadrant/sector#4