Fix static PyABACUS base wrapper calls

[Critsium-xy]

Reminder

• I have read AGENTS.md and docs/developers_guide/agent_governance.md.
• I have linked an issue or explained why this PR does not need one.
• I have added adequate unit tests and/or case tests, or explained why not.
• I have listed the exact verification commands run and their results.
• I have described user-visible behavior changes, including INPUT parameter changes.
• I have explained core-module impact for ESolver, HSolver, ElecState, Hamilt, Operator, Psi, or other source/ changes.
• I have requested any needed governance exception below.

Linked Issue

Fix #7557

Unit Tests and/or Case Tests for my changes

• Commands run:
  • python3 -m compileall -q python/pyabacus/src/pyabacus python/pyabacus/tests/test_base_math.py
  • isolated /tmp build: PYTHONPATH=/tmp/abacus-pydeps-7557 python3 -m pip install --no-build-isolation --target /tmp/abacus-pyinstall-7557 python/pyabacus
  • PYTHONPATH=/tmp/abacus-pyinstall-7557:/tmp/abacus-pydeps-7557 python3 -m pytest python/pyabacus/tests/test_base_math.py -v
  • git diff --check
  • python3 tools/03_code_analysis/agent_governance_check.py --staged
  • python3 tools/03_code_analysis/agent_governance_check.py --base upstream/develop --head HEAD --format text
• Result summary: PyABACUS built successfully; all 4 focused base-math tests passed; compileall, diff, and governance checks passed.
• Checks not run, with reason: the full PyABACUS test suite collected 59 tests but stopped because the environment lacks the optional scipy dependency used by test_hsolver.py. The focused owning test file completed successfully.
• Environment note: an initial attempt to create a venv failed because system Python lacks ensurepip; dependencies and the built package were instead isolated under /tmp with pip --target.

What changed?

• Call the pybind11 base classes explicitly from static Python wrapper methods instead of using zero-argument super().
• Add regression coverage for sphbes_zeros, Simpson_Integral_0toall, and Simpson_Integral_alltoinf.
• Correct the corresponding wrapper example in the PyABACUS contributing guide.

Governance Notes

• INPUT/docs changes: no ABACUS INPUT behavior changed; the relevant PyABACUS contributor example was synchronized.
• Core module impact: none; only Python wrapper dispatch changes.
• Exceptions requested: none.

[mohanchen]

LGTM