Add workflow for language-based PR assignment

[adrienpessu]

This pull request introduces a new GitHub Actions workflow named language-detection-and-assignment.yml to automatically detect the programming language of files changed in a pull request and assign the pull request to specific users based on the detected language.

• Workflow Trigger: Configures the workflow to run on pull request events targeting the main branch.
• Language Detection: Utilizes a script to detect changes in files with extensions specific to Java, Kotlin, JavaScript, TypeScript, Go, Python, Rust, and CodeQL.
• User Assignment:
  • Assigns pull requests to @adrienpessu if changes are detected in Java, Kotlin, JavaScript, TypeScript, or Go files.
  • Assigns pull requests to @GeekMasher for changes in Python, Go, CodeQL, or Rust files.
  • Additionally, assigns pull requests to @felickz for changes in Python, JavaScript, TypeScript, or CodeQL files.

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[GeekMasher]

I think for now this works, it would be nice to have a "YAML file" in this repo and it looks it up