chore(python): drop EOL Python 3.9 and 3.10 support

[owjs3901]

Summary

Closes #10.

Python 3.9 reached end-of-life on 2025-10-31 per devguide.python.org. 3.10 is already in security-only mode and hits EOL in 2026-10.

Meanwhile the project's CI matrix only tests 3.11 / 3.12 / 3.13 / 3.14, so the
equires-python = ">=3.9" claim in bridge/python/pyproject.toml was never actually verified — it was a documentation lie.

Changes

• bridge/python/pyproject.toml: bump requires-python from >=3.9 to >=3.11; drop the 3.9 and 3.10 trove classifiers.
• README.md: update the Python badge and the Development prerequisites from 3.9+ to 3.11+.
• .changepacks/changepack_log_*.json: Minor-version bump for bridge/python/pyproject.toml documenting the drop.

Why 3.11 (not 3.10)

• CI already tests 3.11/3.12/3.13/3.14 only; aligning declared support with what we actually test avoids a repeat of the >=3.9 situation.
• 3.10 is in security-only mode and EOLs in ~6 months anyway.

Verification

• cargo clippy --all-targets --all-features -- -D warnings — clean
• cargo test --workspace — 57 passed, 0 failed
• cargo fmt --check — clean

Impact

Pure packaging metadata change — no Rust / Node code is touched. Existing users on Python 3.9 / 3.10 will get a clear pip resolver error instead of a silently broken wheel.

[github-actions]

Changepacks

dependency-check-updates@0.1.6 → 0.2.0 - bridge/python/pyproject.toml

Minor

• Drop Python 3.9 and 3.10 support (EOL per devguide.python.org). Minimum supported Python is now 3.11, matching the CI test matrix (closes python 3.9 is already EOL #10).