fix(deps): update test Handlebars to 4.5.3

[jbeckwith-oai]

Summary

• constrain the WireMock 2 test graphs in openai-java-core and openai-java-client-okhttp to Handlebars core 4.5.3
• add an end-to-end WireMock response-template test that exercises Handlebars through a real HTTP stub
• address Dependabot alert 91 for CVE-2026-55760 / GHSA-r4gv-qr8j-p3pg

Version choice

Handlebars 4.5.2 is the first release containing the FileTemplateLoader path-traversal fix. This uses 4.5.3 because it also includes the follow-on SpringTemplateLoader arbitrary-file-read fix.

handlebars-helpers intentionally remains at WireMock's requested 4.3.1. WireMock 2.35.2 links helper classes under com.github.jknack.handlebars.helper, while helpers 4.5.3 moved those classes to a different package; aligning both artifacts breaks response templating with NoClassDefFoundError. The vulnerable artifact is Handlebars core, and the new integration test proves the narrow mixed-version graph preserves WireMock's template behavior.

Compatibility

This change affects test configurations only. Handlebars and WireMock are absent from the generated Maven POMs and Gradle module metadata. Published SDK classes remain Java 8 bytecode (class-file major version 52), and no public API, runtime dependency, or Jackson compatibility floor changes. Handlebars 4.5.3 itself requires Java 17, but it runs only in this repository's JDK 21 test toolchain and is never exposed to consumers.

Validation

• dependencyInsight for both modules' test runtime classpaths and the core published-Jackson runtime
• focused response-template test with Jackson 2.14.0 and 2.18.9
• full Gradle check suite with the repository mock server, including ProGuard and R8 checks
• scripts/lint
• scripts/build
• scripts/detect-breaking-changes origin/main
• generated Maven POM and Gradle module metadata inspection
• published core and OkHttp JAR bytecode inspection

Addresses https://github.com/openai/openai-java/security/dependabot/91

[openai-sdks]

OkTest Summary

✅ 237/237 SDK tests passed in 16.084s for Java SDK PR #783.

Test results — 42 files

Test	Result	Time
tests/chat-completions-complex-body.test.ts	✅ Passed	310ms
tests/chat-completions-create.test.ts	✅ Passed	883ms
tests/chat-completions-stream.test.ts	✅ Passed	320ms
tests/files-content-binary.test.ts	✅ Passed	250ms
tests/files-create-multipart.test.ts	✅ Passed	418ms
tests/files-list-pagination.test.ts	✅ Passed	322ms
tests/initialize-config.test.ts	✅ Passed	273ms
tests/instance-isolation.test.ts	✅ Passed	190ms
tests/models-list.test.ts	✅ Passed	166ms
tests/responses-background-lifecycle.test.ts	✅ Passed	480ms
tests/responses-body-method-errors.test.ts	✅ Passed	495ms
tests/responses-cancel-timeout.test.ts	✅ Passed	202ms
tests/responses-cancel.test.ts	✅ Passed	248ms
tests/responses-compact-retries.test.ts	✅ Passed	465ms
tests/responses-compact.test.ts	✅ Passed	410ms
tests/responses-create-advanced-stream.test.ts	✅ Passed	240ms
tests/responses-create-advanced.test.ts	✅ Passed	1.535s
tests/responses-create-disconnect.test.ts	✅ Passed	1.064s
tests/responses-create-errors.test.ts	✅ Passed	282ms
tests/responses-create-malformed-api-responses.test.ts	✅ Passed	296ms
tests/responses-create-retries.test.ts	✅ Passed	264ms
tests/responses-create-stream-failures.test.ts	✅ Passed	223ms
tests/responses-create-stream-timeout.test.ts	✅ Passed	231ms
tests/responses-create-stream-wire.test.ts	✅ Passed	6.052s
tests/responses-create-stream.test.ts	✅ Passed	130ms
tests/responses-create-terminal-states.test.ts	✅ Passed	338ms
tests/responses-create-timeout.test.ts	✅ Passed	207ms
tests/responses-create.test.ts	✅ Passed	720ms
tests/responses-delete.test.ts	✅ Passed	322ms
tests/responses-input-items-errors.test.ts	✅ Passed	288ms
tests/responses-input-items-list.test.ts	✅ Passed	319ms
tests/responses-input-items-options.test.ts	✅ Passed	262ms
tests/responses-input-tokens-count-timeout.test.ts	✅ Passed	245ms
tests/responses-input-tokens-count.test.ts	✅ Passed	217ms
tests/responses-malformed-inputs.test.ts	✅ Passed	4.881s
tests/responses-not-found-errors.test.ts	✅ Passed	387ms
tests/responses-parse.test.ts	✅ Passed	623ms
tests/responses-retrieve-retries.test.ts	✅ Passed	399ms
tests/responses-retrieve.test.ts	✅ Passed	260ms
tests/responses-stored-method-errors.test.ts	✅ Passed	984ms
tests/retry-behavior.test.ts	✅ Passed	3.403s
tests/sdk-error-shape.test.ts	✅ Passed	410ms

View OkTest run #29462769367

_{SDK merge (33879d99f540) · head (9e5437ade0a8) · base (845b2bc87fb0) · OkTest (fd7a761c81c1)}