Run pyspark tests without xdist to prevent fork OOM

xdist workers use fork() to spawn Spark JVM subprocesses, which
temporarily doubles virtual memory and triggers OOM on CI runners.
Exclude pyspark-marked tests from the parallel run and execute them
sequentially in a dedicated pass. Also add the missing @pytest.mark.pyspark
marker to test_pyspark_python_model.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: eakmanrq <6326532+eakmanrq@users.noreply.github.com>

Author: eakmanrq

Makefile

@@ -130,7 +130,7 @@ slow-test:
 	pytest -n auto -m "(fast or slow) and not cicdonly" && pytest -m "isolated" && pytest -m "registry_isolation" && pytest -m "dialect_isolated"
 
 cicd-test:
-	pytest -n auto -m "fast or slow" --junitxml=test-results/junit-cicd.xml && pytest -m "isolated" && pytest -m "registry_isolation" && pytest -m "dialect_isolated"
+	pytest -n auto -m "(fast or slow) and not pyspark" --junitxml=test-results/junit-cicd.xml && pytest -m "pyspark" && pytest -m "isolated" && pytest -m "registry_isolation" && pytest -m "dialect_isolated"
 
 core-fast-test:
 	pytest -n auto -m "fast and not web and not github and not dbt and not jupyter"

tests/core/test_test.py

@@ -1718,6 +1718,7 @@ def test_generate_input_data_using_sql(mocker: MockerFixture, tmp_path: Path) ->
         )
 
 
+@pytest.mark.pyspark
 def test_pyspark_python_model(tmp_path: Path) -> None:
     spark_connection_config = SparkConnectionConfig(
         config={