chore: update flags project workflow SHA

[dustinbyrne]

💡 Motivation and Context

The repository pins an older revision of the shared feature flags project-board workflow. This rollout keeps SDK callers aligned with the current reusable workflow contract.

Related rollout: PostHog/posthog-ruby#255

💚 How did you test it?

• Parsed .github/workflows/call-flags-project-board.yml with Ruby's YAML parser.
• Ran git diff --check.
• Verified that the pinned reusable workflow declares both credentials passed by the caller.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm changeset to generate a changeset file

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Pi compared the SDK callers with the current shared workflow, applied the requested workflow update, and validated the YAML and diff. A fresh-context builtin reviewer checked the caller and reusable-workflow contract and found no issues.

[greptile-apps]

Prompt To Fix All With AI

### Issue 1
.github/workflows/call-flags-project-board.yml:20-22
**Undeclared reusable-workflow secrets**

When a pull request invokes this job, the caller passes `PROJECT_BOARD_BOT_APP_ID` and `PROJECT_BOARD_BOT_PRIVATE_KEY`, but the pinned reusable workflow declares neither secret under `workflow_call.secrets`, causing GitHub Actions to reject the invocation before the project-board job runs.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "chore: update flags project workflow SHA" | Re-trigger Greptile}