chore(main): release 9.18.0

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🤖 I have created a release beep boop

9.18.0 (2026-09-25)

Features

• Add retry state for RETRY-spec backoff (#522) (e734558)
• Drive repeating tasks from a delay source (9abe8cb)
• Retry indefinitely after a data source failure instead of stopping permanently in FDv1 (e17e173)
• warn that payload filtering has no effect with FDv2 (#518) (296311f)
• Warn when the SDK is used in a forked process without postfork (#512) (75402e9)

Bug Fixes

• Add async modules to the readthedocs API reference (#513) (f40d3b2)
• Log the cached-data evaluation warning only once per client (#520) (59ce998)
• Read all items when a collection is empty (#524) (1087147)
• Repeating task wait duration is no longer reduced by a slow callback duration. (9abe8cb)
• Report a distinct User-Agent for the async client (#516) (514c467)
• Warn and use the documented default for an invalid poll interval or initial reconnect delay (e17e173)

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This PR was generated with Release Please. See documentation.

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Note

Overview
This PR cuts release 9.18.0 by bumping the package version in pyproject.toml, ldclient/version.py, .release-please-manifest.json, and the provenance docs example, and by adding the 9.18.0 section to CHANGELOG.md.

There is no application code in the diff—Release Please is packaging work that was already merged. The new changelog highlights FDv1 data-source resilience (indefinite retry after failures, RETRY-spec backoff state, repeating tasks driven by a delay source, and sane defaults/warnings for invalid poll/reconnect settings), operational warnings (forked process without postfork, FDv2 payload filtering), and fixes (empty-collection reads, repeating-task timing, one-time cached-data warnings, distinct async User-Agent, ReadTheDocs async API docs).

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[github-actions]

🤖 Created releases:

• 9.18.0

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