Move gensim and rdflib to optional extras to slim core install

[Copilot]

gensim and rdflib were bundled as core dependencies despite being non-core functionality. This change moves them to optional extras so base installs and wheel metadata stay lean while preserving access through feature extras.

• Dependency surface cleanup

  • Removed gensim and rdflib from [project].dependencies in pyproject.toml.
  • Added both packages to the algos extra.
  • Included them in the optional meta-extra to keep extra composition consistent.

• Docs alignment

  • Updated installation/dependency docs to classify gensim and rdflib as optional algorithm tooling instead of core requirements.

• Behavioral guardrails in tests

  • Added tests/test_dependency_cleanup.py to assert:
    • gensim/rdflib are absent from core deps.
    • gensim/rdflib are present in algos.
  • Updated wrapper benchmark test to skip when gensim is not installed (optional-dependency-safe test behavior).

[project]
dependencies = [
  "numpy>=1.19.0",
  "scipy>=1.5.0",
  "networkx>=2.5",
  # no gensim / rdflib here
]

[project.optional-dependencies]
algos = [
  "python-louvain>=0.16",
  "cdlib>=0.3.0",
  "gensim>=4.0.0",
  "rdflib>=6.0.0",
]

[SkBlaz]

@copilot ci fails

[Copilot]

@copilot ci fails

Fixed the CI failure in commit a2d79dc by making tests/property/test_wrappers_sparse_properties.py optional-dependency-safe (pytest.importorskip("gensim")), matching the move of gensim out of core dependencies.