ci: use shared gh-actions/actions/contract-tests action

[kinyoklion]

Requirements

• I have added test coverage for new or changed functionality
• I have followed the repository's pull request submission guidelines
• I have validated my changes against all supported platform versions

Related issues

N/A — CI-only change.

Describe the solution you've provided

Replace the local .github/actions/contract-tests action with the shared launchdarkly/gh-actions/actions/contract-tests@contract-tests-v1 action.

The local action accepted a token input but never forwarded it, so GITHUB_TOKEN was not used when downloading the contract test harness (leading to potential rate limiting). The shared action properly passes the token both as an Authorization header on the curl request and as the GITHUB_TOKEN env var for the downloader script.

Since the shared action only handles downloading and running the harness (not building/starting the test service), the build and start steps are now explicit workflow steps.

Describe alternatives you've considered

Could have fixed the local action to forward the token to the Makefile, but using the shared action is more maintainable and consistent with other SDK repos.

Additional context

Both java-server-sdk.yml and nightly-contract-tests.yml are updated. The Makefile is left unchanged so local development workflows still work."

Link to Devin session: https://app.devin.ai/sessions/02984ba491764e598f041b70041206ba
Requested by: @kinyoklion

---

Note

Low Risk
Low risk to product code since changes are CI-only, but there is some workflow risk if the shared contract-tests action inputs/behavior differ and could cause contract-test job failures.

Overview
Updates the java-server-sdk and Nightly Contract Tests workflows to stop using the local .github/actions/contract-tests composite action and instead run contract tests via launchdarkly/gh-actions/actions/contract-tests@contract-tests-v1.

Because the shared action only runs the harness, the workflows now explicitly make build-contract-tests and start the service in the background before running separate v2 and v3 harness runs (including passing GITHUB_TOKEN, port 8000, and skip/long-running parameters). The obsolete local action definition is removed.

^{Reviewed by Cursor Bugbot for commit fba4f0b. Bugbot is set up for automated code reviews on this repo. Configure here.}

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring