fix(tests): remove unused pytest import and fix stale docstring path (HYBIM-809)

- Drop unused `import pytest` from test_api_headers.py (F401, flagged by reviewer)
- Update patch_http_validation_error.py docstring example path from
  src/galileo/ to src/splunk_ao/ (pre-existing stale reference)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: etserend

scripts/patch_http_validation_error.py

@@ -18,7 +18,7 @@
 ``scripts/auto-generate-api-client.sh``::
 
     python scripts/patch_http_validation_error.py \\
-        src/galileo/resources/models/http_validation_error.py
+        src/splunk_ao/resources/models/http_validation_error.py
 
 Exit codes
 ----------

tests/test_api_headers.py

@@ -1,7 +1,5 @@
 """Tests for Splunk-AO-SDK header in API calls."""
 
-import pytest
-
 from importlib.metadata import PackageNotFoundError
 from unittest.mock import patch