Fix DCO action tag and add tests/__init__.py for CI imports

- DCO tag: v0.5.0 → 0.5.0 (repo uses unversioned tags)
- Add tests/__init__.py so `from tests.conftest import ...` works in CI
- Fix import ordering in test_bootstrap.py

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: deborahjacob-botanu

.github/workflows/ci.yml

@@ -101,6 +101,6 @@ jobs:
         with:
           fetch-depth: 0
       - name: DCO check
-        uses: christophebedard/dco-check@v0.5.0
+        uses: christophebedard/dco-check@0.5.0
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

tests/__init__.py

@@ -0,0 +1,2 @@
+# SPDX-FileCopyrightText: 2026 The Botanu Authors
+# SPDX-License-Identifier: Apache-2.0

tests/unit/test_bootstrap.py

@@ -644,6 +644,7 @@ def test_otel_traces_sampler_env_var_warning(self):
     def test_conftest_uses_always_on(self):
         """Test provider must also use ALWAYS_ON to match production behavior."""
         from opentelemetry.sdk.trace.sampling import ALWAYS_ON
+
         from tests.conftest import _get_or_create_provider
 
         provider, _ = _get_or_create_provider()