chore(main): release 9.15.0

[github-actions]

🤖 I have created a release beep boop

9.15.0 (2026-02-04)

Features

• Drop support for python 3.9 (#393) (5b761bd)

Bug Fixes

• Add context manager for clearer, safer locks (#396) (beca0fa)
• Address potential race condition in FeatureStore update_availability (#391) (31cf487)
• Allow modifying fdv2 data source options independent of main config (#403) (d78079e)
• Prevent immediate polling on recoverable error (#399) (da565a2)
• Redis store is considered initialized when $inited key is written (e99a27d)
• Stop FeatureStoreClientWrapper poller on close (#397) (468afdf)
• Update DataSystemConfig to accept list of synchronizers (#404) (c73ad14)
• Update reason documentation with inExperiment value (#401) (cbfc3dd)
• Update Redis to write missing $inited key (e99a27d)

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Note

Low Risk
Primarily a version bump and documentation/changelog updates with no functional code changes in this PR.

Overview
Publishes release 9.15.0 by bumping version references across the repo (ldclient/version.py, pyproject.toml, and .release-please-manifest.json).

Updates CHANGELOG.md with the 9.15.0 release notes (including dropping Python 3.9 support and several bug fixes) and updates PROVENANCE.md to reference the new version for SLSA verification instructions.

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