chore: include AISdkInfo in extra-files to keep version synced

[mattrmc1]

Summary

Adds AISdkInfo.java to Release Please extra-files so AISdkInfo.VERSION stays in sync with gradle.properties on each release PR. Follows the same pattern as the core Java server SDK and .NET AI SDK.

The SDK-info event test now references the AISdkInfo constants directly so future version bumps can't leave the expectation stale. No runtime behavior change.

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Note

Low Risk
Release automation and test expectations only; no production logic changes.

Overview
Release Please for lib/sdk/server-ai now bumps AISdkInfo.java alongside gradle.properties, matching the core server SDK’s Version.java pattern so AISdkInfo.VERSION stays aligned on release PRs.

constructorEmitsSdkInfoEvent in LDAIClientImplTest asserts against AISdkInfo.NAME, VERSION, and LANGUAGE instead of hardcoded literals, so version bumps won’t leave the test out of date. No runtime behavior change.

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