Update pyproject.toml and requirements-dev.txt for semantic release 🚀

This commit includes updates to the `pyproject.toml` and `requirements-dev.txt` files. The `pyproject.toml` file now includes a new section for `semantic_release` with a `version_variable` set to `aicodebot:version`. This change allows for automated versioning using the semantic-release tool.

In the `requirements-dev.txt` file, the `python-semantic-release` package has been added. This package provides the semantic-release command line tool, which automates the whole package release workflow including: determining the next version number, generating the release notes and publishing the package.

These changes aim to streamline the release process, making it more efficient and consistent. 📦🔄