ci: refactor release process

[nilsgstrabo]

Handle stable release versions only.

Also configured permissions for existing pr workflow

[Copilot]

Pull Request Overview

This PR refactors the release process to handle stable release versions only, moving from a tag-based release system to an automated workflow-based approach using conventional commits and pull requests.

Key changes:

• Implements automated release workflow using conventional commits and git-cliff for changelog generation
• Adds GitHub workflows for preparing release PRs and creating releases/tags
• Updates documentation to reflect the new trunk-based development and release process

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
cliff.toml	Adds git-cliff configuration for automated changelog generation with conventional commit parsing
README.md	Updates documentation to describe new trunk-based development workflow and automated release process
.github/workflows/prepare-release-pr.yml	Adds workflow to automatically prepare release pull requests based on conventional commits
.github/workflows/pr.yaml	Adds explicit permissions for existing PR workflow jobs
.github/workflows/create-releases.yml	Adds workflow to create GitHub releases and tags from approved release PRs

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