Allow osteosarc 0.15 in test-data extra (10.11.10)

[iskandr]

Osteosarc 0.15.5 errors during setup for all five snapshot dataset tests because the test-data extra and fixture cap the version below 0.15. Widen both bounds to >=0.14.4,<0.16, retaining support for 0.14.4 and allowing the verified 0.15.x adapter.

Update the test documentation and CI comment, and release as 10.11.10. Runtime code and snapshot data are unchanged.

Validation:

• Reproduced all five setup errors with osteosarc 0.15.5 before the change; all five pass afterward.
• ./lint.sh, python -m pip check, and python -m mkdocs build --strict pass.
• TEST_SH_MAX=4 ./test.sh: 3,240 passed with osteosarc 0.15.5 (92% coverage).

Closes #581.