Restore 100% test coverage for tests/conftest.py and enforce in CI

Add pragma: no cover to Valkey-specific code paths that are not executed
in the default test environment. Also add --cov-fail-under=100 to CI
to ensure coverage regressions are caught automatically.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: chrisguidry

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
       - name: Run tests
         env:
           REDIS_VERSION: ${{ matrix.redis-version }}
-        run: uv run pytest --cov-branch --cov-report=xml --cov-report=term-missing:skip-covered
+        run: uv run pytest --cov-branch --cov-fail-under=100 --cov-report=xml --cov-report=term-missing:skip-covered
 
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v5

tests/conftest.py

@@ -91,9 +91,9 @@ def redis_server(testrun_uid: str, worker_id: str) -> Generator[Container, None,
                 redis_port = s.getsockname()[1]
 
             # Determine Docker image based on version
-            if REDIS_VERSION.startswith("valkey-"):
-                version = REDIS_VERSION.replace("valkey-", "")
-                image = f"valkey/valkey:{version}"
+            if REDIS_VERSION.startswith("valkey-"):  # pragma: no cover
+                version = REDIS_VERSION.replace("valkey-", "")  # pragma: no cover
+                image = f"valkey/valkey:{version}"  # pragma: no cover
             else:
                 image = f"redis:{REDIS_VERSION}"