Fix issues running from pip install

[ItMightBeKaraoke]

• pyproject.toml: lyrics_transcriber/utils/cli.py "import pkg_resources" depends on setuptools. Version spec may need to be updated, I just picked one roughly around python 3.9 era.
• poetry.lock - Also missing setuptools dep
• lyrics_transcriber/transcriber.py - the llm prompt paths are relative and if the user installed with pip, would only work if the user is in the site_packages directory

I don't have openai credits to fully test, but to reproduce the issue:

python3 -m venv venv
. venv/bin/activate # or activation script of choice
pip install lyrics-transcriber
lyrics-transcriber # ModuleNotFoundError: No module named 'pkg_resources'
pip install setuptools
lyrics-transcriber --artist ARTIST --title TITLE FILE # No such file or directory: 'lyrics_transcriber/llm_prompts/llm_prompt_lyrics_matching_andrew_handwritten_20231118.txt'

[ItMightBeKaraoke]

Ignore the previous PR that I closed. Same changes, but bad author metadata...