Mark test_nbconvert as a flaky test

requirements-dev.txt

@@ -2,6 +2,7 @@ docker
 plumbum
 pre-commit
 pytest
+pytest-retry
 # `pytest-xdist` is a plugin that provides the `--numprocesses` flag,
 # allowing us to run `pytest` tests in parallel
 pytest-xdist

tests/all-spark-notebook/test_spark_notebooks.py

@@ -11,6 +11,7 @@ LOGGER = logging.getLogger(__name__)
 THIS_DIR = Path(__file__).parent.resolve()
 
 
+@pytest.mark.flaky(retries=3, delay=1)
 @pytest.mark.parametrize(
     "test_file",
     ["issue_1168", "local_pyspark", "local_sparklyr", "local_sparkR"],