Update dependencies and pyproject.toml

[katie-lamb]

In the process of running a data update I thought it would be helpful to update some dependencies and simplify where we name dependencies. Initially it was spread between requirements.txt and setup.py. But setup.py was recently removed. I thought it would be simpler if everything was in pyproject.toml. This PR makes the following changes:

• Removes PUDL as a dependency since we're now just accessing PUDL tables directly from AWS
• Updates some key dependencies to their latest version - namely python and pandas
• Removes requirements.txt in favor of putting all dependencies under pyproject.toml. It seems like the main advantage of requirements.txt was having one place where Docker could install all development dependencies, but I instead had Docker just download the dbcp package + all the dependencies in pyproject.toml. I'm not that familiar with Docker so I'm not sure if this is problematic or not the standard convention.

Remaining To Do:

• Add more to the DBCP documentation google doc about comparison notebooks and running them from within the docker container
• Check on things like dependabot to see if it's keeping dependencies updated
• Separate out development dependencies from package dependencies
• Debug ETL with updated dependencies -- namely python 3.12 and pandas 2.0
• Compare data warehouse and data mart to see if anything has changed from newer versions of Python and pandas