build: drop python 3.10, support 3.15, update CI and pre-commit hooks

[tlambert03]

• requires-python = ">=3.11", add 3.15 classifier, ruff target-version = "py311" (+ resulting autofixes: StrEnum, typing.Self)
• 3.15 support: pydantic-core only ships cp315 wheels from 2.48, which requires pydantic>=2.14.0b1 (2.14 isn't final yet), so there's a python_version >= '3.15' marker pinning the pre-release. The b1 can be dropped once 2.14 is out.
• CI:
  • test matrix is now 3.11–3.15, with lowest-direct on both 3.11 and 3.15 (UV_RESOLUTION env pattern, like yaozarrs/ome-writers)
  • new lint job running prek run --all-files
  • all actions updated (checkout@v7, setup-uv@v10.1.0, upload-artifact@v7, download-artifact@v8, setup-headless-display-action@v5, configure-pages@v6, action-gh-release@v3, build-and-inspect-python-package@v3.0.1)
  • the baipp bump fixes the Invalid distribution metadata: '2.5' twine failure that has been breaking scheduled runs on main
• prek autoupdate, add actionlint hook; ruff 0.16 now formats python code blocks in docs/getting_started.md
• test_icon_follows_theme assumed a device pixel ratio of 1 and failed on HiDPI screens; pixel coordinates are now scaled by the DPR

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.49%. Comparing base (4c11aea) to head (e1583a1).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #289   +/-   ##
=======================================
  Coverage   99.49%   99.49%           
=======================================
  Files          31       31           
  Lines        1971     1971           
=======================================
  Hits         1961     1961           
  Misses         10       10           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.