chore: remove legacy setuptools scaffolding and tidy repo

Delete setup.py, setup.cfg, tox.ini and the stray root __init__.py.
Remove eight unused runtime dependencies (ruamel.yaml, pandas, chardet,
matplotlib, scipy, sphinx, and the stdlib-shadowing pathlib/asyncio),
drop the testing extra in favor of the dev dependency group, and trim
the deptry ignores accordingly (lock: 220 to 187 packages). Update
README, CONTRIBUTING, docs/dev.md and test docstrings to the uv/make
workflow; mark CHANGELOG as release-notes-based until
python-semantic-release lands

Author: raederan

AUTHORS.md

@@ -1,5 +1,11 @@
 # Changelog
 
+> **Note:** This file is no longer updated manually. Changes since
+> v0.12.0 are tracked in the
+> [GitHub Releases](https://github.com/OpenSemanticLab/osw-python/releases).
+> Automated changelog generation (python-semantic-release) is planned;
+> the historical entries below are preserved for reference.
+
 ## Version v0.12.0
  - rework ontology import (BREAKING, see examples/ontology_import.py)
  - add in-memory credentials in CredentialManager

CHANGELOG.md

@@ -7,4 +7,7 @@ authors:
   - family-names: Gold
     given-names: Lukas
     orcid: https://orcid.org/0000-0001-7444-2969
+  - family-names: Räder
+    given-names: Andreas
+    orcid: https://orcid.org/0000-0002-2673-0832
 title: OpenSemanticWorld Python Package (osw-python)