chore: upgrade temporal SDK to 1.20.0

[daryllimyt]

Summary

• Upgrade temporalio from 1.19.0 to 1.20.0.
• Refresh the lockfile, including the compatible nexus-rpc transitive bump.

Why

Temporal Python SDK 1.20.0 enables worker heartbeat reporting from SDK workers. This lets us see worker heartbeat/worker-list visibility in Temporal Cloud for deployed Tracecat workers, subject to the Temporal Cloud/server-side feature support and dynamic config being enabled.

Verification

• uv run python - <<'PY' ... confirmed temporalio.__version__ == "1.20.0"
• uv run pytest tests/unit/test_schedule_create_status.py tests/unit/test_registry_sync_base_service.py -q
• uv run pytest tests/temporal/test_agent_config_workflow_boundary.py::test_agent_config_payload_survives_temporal_activity_boundary -q
• uv run ruff check .

---

Summary by cubic

Upgrade temporalio from 1.19.0 to 1.20.0 to enable SDK worker heartbeats and improve worker visibility in Temporal Cloud. Refreshed the lockfile, including a compatible nexus-rpc transitive bump.

^{Written for commit 7c23fa3. Summary will update on new commits. Review in cubic}

[zeropath-ai]

✅ No security or compliance issues detected. Reviewed everything up to 7c23fa3.

Security Overview

• 🔎 Scanned files: 2 changed file(s)
• 🔗 Scan Link: https://zeropath.com/app/repositories/00dffd6c-8834-4dc9-b6d8-b44cd1622986?scanId=470e1d71-235c-4d51-a48a-7af1b222c603&codeScanTypes=PrScan&tab=issues

Detected Code Changes

Change Type	Relevant files
Configuration changes	► pyproject.toml     Update temporalio dependency to 1.20.0 ► uv.lock     Update temporalio package version to 1.20.0     Update nexus-rpc package version to 1.2.0

[cubic-dev-ai]

No issues found across 2 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

_{Re-trigger cubic}