Allow configuring Python SDK retry methods

[JaviChulvi]

Allow callers to opt safe-to-repeat methods into the existing Python SDK retry loop with retry_methods=("POST",). Defaults stay unchanged. This lets training metrics and checkpoint signing reuse SDK retries instead of maintaining another retry loop in Ultralytics. The generator remains API-independent.

Merge this first so SDK automation can generate and publish the updated client. Then ultralytics/ultralytics#26190 can use it.

Validated with generator checks, sync/async SDK tests, and live local-training, upload, and cancellation E2E.

[UltralyticsAssistant]

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[UltralyticsAssistant]

🔍 PR Review

_{Made with ❤️ by Ultralytics Actions}

Reviewed the retry_methods propagation, default behavior, sync/async generated clients, retry predicate, documentation, and existing generator patterns. The default GET/HEAD/OPTIONS behavior is preserved, existing JSON 429 retries remain intact, and the opt-in method configuration is API-independent. LGTM; no concrete defects found.