Adopting ruff formatter

Makefile

@@ -25,13 +25,11 @@ rebuild-lockfiles: .pdm
 
 .PHONY: format  ## Auto-format python source files
 format: .pdm
-	pdm run black $(sources)
 	pdm run ruff --fix $(sources)
 
 .PHONY: lint  ## Lint python source files
 lint: .pdm
 	pdm run ruff $(sources)
-	pdm run black $(sources) --check --diff
 
 .PHONY: codespell  ## Use Codespell to do spellchecking
 codespell: .pre-commit

docs/contributing.md

@@ -90,8 +90,8 @@ Run tests and linting locally to make sure everything is working as expected.
 ```bash
 # Run automated code formatting and linting
 make format
-# Pydantic uses black and ruff
-# (https://github.com/ambv/black, https://github.com/charliermarsh/ruff)
+# Pydantic uses ruff
+# https://github.com/charliermarsh/ruff
 
 # Run tests and linting
 make