ci: Add Dependabot PR title workflow; tweak templates

[DylanDevelops]

Pull Request Checklist

• I have read and followed the contribution guidelines.
• My pull request targets the main branch of tmpo.
• I have tested these changes locally on my machine.

Description

This pull request updates how Dependabot pull request titles are managed and improves author attribution in commit messages. The main changes include removing commit message prefix settings from the Dependabot configuration and introducing a workflow that automatically adds standardized prefixes to Dependabot PR titles. Additionally, commit messages now display the author's name in bold for better visibility.

Dependabot PR Title Standardization:

• Added a new GitHub Actions workflow (.github/workflows/dependabot-pr-title.yml) that automatically prefixes Dependabot pull request titles with either build(deps): or ci(github-actions):, depending on the type of update. This ensures consistent PR title formatting and removes the need for manual or configuration-based prefixes.
• Removed the commit-message prefix settings from the Dependabot configuration for both Go modules and GitHub Actions, delegating PR title prefixing to the new workflow. (.github/dependabot.yml) [1] [2]

Commit Message Formatting:

• Updated the commit message template in cliff.toml to display the commit author's name in bold instead of showing the remote username, improving clarity and attribution.