[dagster-airlift] Fix dbt example tests (#25778)

## Summary & Motivation
We weren't constructing env correctly, which was causing tests to fail. This fixed for me locally.

.buildkite/dagster-buildkite/dagster_buildkite/steps/packages.py

@@ -368,11 +368,10 @@ def k8s_extra_cmds(version: str, _) -> List[str]:
     PackageSpec(
         "examples/experimental/dagster-airlift",
     ),
-    # Skipping for now due to flaky integration tests.
-    # PackageSpec(
-    #     "examples/experimental/dagster-airlift/examples/dbt-example",
-    #     always_run_if=has_dagster_airlift_changes,
-    # ),
+    PackageSpec(
+        "examples/experimental/dagster-airlift/examples/dbt-example",
+        always_run_if=has_dagster_airlift_changes,
+    ),
     PackageSpec(
         "examples/experimental/dagster-airlift/examples/perf-harness",
         always_run_if=has_dagster_airlift_changes,

examples/experimental/dagster-airlift/examples/dbt-example/Makefile

@@ -27,7 +27,7 @@ setup_local_env:
 	mkdir -p $(MIGRATING_AIRFLOW_HOME)
 	mkdir -p $(DAGSTER_HOME)
 	chmod +x ../../scripts/airflow_setup.sh
-	../../scripts/airflow_setup.sh $(MAKEFILE_DIR)/dbt_example/migrating_airflow_dags $(MIGRATING_AIRFLOW_HOME)
+	AIRFLOW_HOME=$(MIGRATING_AIRFLOW_HOME) ../../scripts/airflow_setup.sh $(MAKEFILE_DIR)/dbt_example/migrating_airflow_dags
 	$(MAKE) dbt_setup
 
 not_proxied:
@@ -57,7 +57,7 @@ run_complete:
 	dagster dev -m dbt_example.dagster_defs.complete -p 3333
 
 wipe: ## Wipe out all the files created by the Makefile
-	rm -rf $(AIRFLOW_HOME) $(DAGSTER_HOME)
+	rm -rf $(MIGRATING_AIRFLOW_HOME) $(DAGSTER_HOME)
 
 wipe_dagster: ## Wipe out all the files created by the Makefile
 	rm -rf $$DAGSTER_HOME