[ac1982]

Make Python compatibility explicit in the existing CircleCI configuration and package classifiers, addressing #297.

Add a parameterized compatibility job for Python 3.10–3.15 using the corresponding cimg/python images. Each version runs the existing suite with Poppler and again after removing it. Use python -m pip and python -m coverage so the selected interpreter runs installation and tests. Keep the existing coverage-upload job, and add classifiers for the newly tested 3.11–3.15 versions.

Validation:

• Python 3.10–3.15: each ran 110 tests successfully with Poppler (10 skips under CIRCLECI=true) and without Poppler (106 skips). Local no-Poppler runs restricted PATH instead of uninstalling host tools.
• Python 3.14 additionally ran the full suite without the CI flag: 110 tests, 2 skips, including the large PDF conversions.
• Official CircleCI CLI 1.7.0 validates the configuration. All six image tags exist. The actual CircleCI jobs have not been run locally.

Prepared with OpenAI Codex assistance.