Maintenance: resolve flake8-bugbear B036 errors

[jayaddison]

Resolves two B036 errors reported by recent versions of the flake8-bugbear plugin for flake8.

• Ignores one error report in case 1-of-2 where the exception is intentionally not re-raised.
• Adjusts the exception handler base class in case 2-of-2 where the exception handler was introduced to handle the non-existence of an imported module.
• fixes #1941

Checklist:

• [ ] ~~Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.~~
• [ ] ~~Add or update relevant docs, in the docs folder and in code.~~
• [ ] ~~Add an entry in CHANGES.rst summarizing the change and linking to the issue.~~
• [ ] ~~Add .. versionchanged:: entries in any relevant code docs.~~
• [x] Run pre-commit hooks and fix any issues.
• [x] Run pytest and tox, no tests failed (note: tox tested Python versions 3.11.8, 3.12.2).