Fix CI issue running integration tests (#640)

At the moment, all PRs are failing due to issues with integration tests
not being able to run. An example of error message:
```
FAILED tests/test_example_dags.py::test_example_dag[extract_dag] - assert not {'/home/runner/work/astronomer-cosmos/astronomer-cosmos/dev/dags/example_cosmos_python_models.py': 'Traceback (most recent call last):\n  File "/opt/hostedtoolcache/Python/3.9.18/x64/lib/python3.9/selectors.py", line 416, in select\n    fd_event_list = self._selector.poll(timeout)\n  File "/home/runner/.local/share/hatch/env/virtual/astronomer-cosmos/Za_bFbg4/tests.py3.9-2.4/lib/python3.9/site-packages/airflow/utils/timeout.py", line 69, in handle_timeout\n    raise AirflowTaskTimeout(self.error_message)\nairflow.exceptions.AirflowTaskTimeout: DagBag import timeout for /home/runner/work/astronomer-cosmos/astronomer-cosmos/dev/dags/example_cosmos_python_models.py after 30.0s.\nPlease take a look at these docs to improve your DAG import time:\n* https://airflow.apache.org/docs/apache-airflow/2.4.0/best-practices.html#top-level-python-code\n* https://airflow.apache.org/docs/apache-airflow/2.4.0/best-practices.html#reducing-dag-complexity, PID: 2558\n'}
```
This issue relates to #520 - something we'll be soon working on.

In the meantime, we're increasing the DAG Parsing time in the CI - so
our tests can run again.

We should also review how we run the integration tests - we probably do
not need to run all DAGs against the Python x Airflow matrix, and we
could parallelise some of those.

.github/workflows/test.yml

@@ -121,8 +121,9 @@ jobs:
         env:
           AIRFLOW_HOME: /home/runner/work/astronomer-cosmos/astronomer-cosmos/
           AIRFLOW_CONN_AIRFLOW_DB: postgres://postgres:[email protected]:5432/postgres
-          PYTHONPATH: /home/runner/work/astronomer-cosmos/astronomer-cosmos/:$PYTHONPATH
           AIRFLOW_CONN_DATABRICKS_DEFAULT: ${{ secrets.AIRFLOW_CONN_DATABRICKS_DEFAULT }}
+          AIRFLOW__CORE__DAGBAG_IMPORT_TIMEOUT: 90.0
+          PYTHONPATH: /home/runner/work/astronomer-cosmos/astronomer-cosmos/:$PYTHONPATH
           DATABRICKS_HOST: ${{ secrets.DATABRICKS_HOST }}
           DATABRICKS_TOKEN: ${{ secrets.DATABRICKS_TOKEN }}
           DATABRICKS_WAREHOUSE_ID: ${{ secrets.DATABRICKS_WAREHOUSE_ID }}
@@ -192,6 +193,7 @@ jobs:
           AIRFLOW_CONN_AIRFLOW_DB: postgres://postgres:[email protected]:5432/postgres
           PYTHONPATH: /home/runner/work/astronomer-cosmos/astronomer-cosmos/:$PYTHONPATH
           AIRFLOW_CONN_DATABRICKS_DEFAULT: ${{ secrets.AIRFLOW_CONN_DATABRICKS_DEFAULT }}
+          AIRFLOW__CORE__DAGBAG_IMPORT_TIMEOUT: 90.0
           DATABRICKS_HOST: ${{ secrets.DATABRICKS_HOST }}
           DATABRICKS_TOKEN: ${{ secrets.DATABRICKS_TOKEN }}
           DATABRICKS_WAREHOUSE_ID: ${{ secrets.DATABRICKS_WAREHOUSE_ID }}
@@ -256,6 +258,7 @@ jobs:
         env:
           AIRFLOW_HOME: /home/runner/work/astronomer-cosmos/astronomer-cosmos/
           AIRFLOW_CONN_AIRFLOW_DB: postgres://postgres:[email protected]:5432/postgres
+          AIRFLOW__CORE__DAGBAG_IMPORT_TIMEOUT: 90.0
           PYTHONPATH: /home/runner/work/astronomer-cosmos/astronomer-cosmos/:$PYTHONPATH
           AIRFLOW_CONN_DATABRICKS_DEFAULT: ${{ secrets.AIRFLOW_CONN_DATABRICKS_DEFAULT }}
           DATABRICKS_HOST: ${{ secrets.DATABRICKS_HOST }}