[Batch] Fix runtime timeout setting

[scarlet25151]

Pull Request Description

• Preserving compatibility with legacy runtime _wait_ready(handle) hooks while still forwarding wait_mode to newer implementations.
• Adding per-job client.request_timeout_seconds metadata with minimum timeout validation.
• Adding focused regression tests for readiness hook compatibility and request timeout metadata validation/round-trip behavior.

Related Issues

Resolves: #[Insert issue number(s)]

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[gemini-code-assist]

Code Review

This pull request introduces backward compatibility for legacy runtimes by dynamically inspecting whether _wait_ready accepts the wait_mode parameter. It also adds a request_timeout_seconds configuration option to ClientConfig with a minimum value of 1.0 second, supported by new unit tests. Feedback is provided to improve the robustness of the signature inspection by catching broader exceptions and returning a safer fallback value of False to prevent potential runtime errors on legacy implementations.