ci: simplify semantic release

[a-klos]

This pull request updates the deployment pipeline and Helm configuration to streamline image tagging and simplify Helm chart updates. The main change is that all Docker images are now tagged with both the version and latest, and the Helm chart is updated to use the latest tag for all services. Additionally, the workflow steps that previously automated Helm value updates and commits have been removed, reflecting a shift to a simpler release process.

Image Tagging and Helm Chart Updates:

• Updated all Docker build commands in the Makefile to tag images with both the specific version and latest, ensuring the most recent build is always available under the latest tag.
• Changed the Helm values in infrastructure/rag/values.yaml for all services (mcp-server, rag-backend, frontend, admin-backend, document-extractor, admin-frontend) to use the latest image tag instead of a specific version. [1] [2] [3] [4] [5]

CI/CD Workflow Simplification:

• Removed the update-helm-values and commit-helm-changes steps from .github/workflows/semantic-release.yml, so Helm values are no longer automatically updated and committed during release.
• Removed the summary line indicating the Helm chart was updated from the workflow output.