[chore] Stricter ruff rules (#282)

* [chore] Stricter ruff rules

* [chore] Furture lint rules and removal of flake8

* [ci] Bump github action versions

* [chore] Add additional test coverage

* Revert RNG switch to np.random.default_rng()

Restore use of the global np.random state in pseudo_Obs (misc.py) and the
prior id generation (fits.py), keeping seed behavior unchanged. The switch
to a module-local generator is out of scope for this lint-focused PR.

* Silence NPY002 on intentional legacy np.random calls

The RNG migration was reverted to keep np.random.seed() behavior, so add
per-line noqa: NPY002 on the three legacy np.random calls instead of the
Generator API.

* [Fix] Fix exception messages

pyproject.toml

@@ -2,5 +2,15 @@
 requires = ["setuptools >= 63.0.0", "wheel"]
 build-backend = "setuptools.build_meta"
 
+[tool.ruff]
+target-version = "py310"
+
 [tool.ruff.lint]
-ignore = ["F403"]
+extend-select = ["E", "W", "I", "B", "PIE", "PLE", "PLW", "UP", "NPY", "RUF"]
+ignore = [
+    "F403",     # star imports in __init__ files are intentional
+    "E501",     # line too long
+    "PLC0415",  # import outside top level
+    "PLW2901",  # redefined loop name (too noisy)
+    "RUF002",   # ambiguous unicode in docstrings (Greek letters)
+]