Update Dependabot to support pyproject.toml files

[aatmanvaidya]

Update this .github/dependabot.yml action to support checks for pyproject.toml files. Link to the file.

There is a possibility that Dependabot may not fully support pyproject.toml files. The purpose of this issue is also to conduct a very small exploration to confirm whether Dependabot can handle dependency updates for pyproject.toml files and identify any limitations, if present.