Use sys.exit instead of exit (dbt-labs#5627) (dbt-labs#5640)

* Use sys.exit instead of exit

* Add changelog

Co-authored-by: varun-dc <91232924+varun-dc@users.noreply.github.com>

.changes/unreleased/Fixes-20220808-112001.yaml

@@ -0,0 +1,7 @@
+kind: Fixes
+body: Use sys.exit instead of exit
+time: 2022-08-08T11:20:01.838171926-04:00
+custom:
+  Author: varun-dc
+  Issue: "5621"
+  PR: "5627"

core/dbt/task/init.py

@@ -3,6 +3,7 @@
 from pathlib import Path
 import re
 import shutil
+import sys
 from typing import Optional
 
 import yaml
@@ -302,7 +303,7 @@ def run(self):
         available_adapters = list(_get_adapter_plugin_names())
         if not len(available_adapters):
             print("No adapters available. Go to https://docs.getdbt.com/docs/available-adapters")
-            exit(1)
+            sys.exit(1)
         project_name = self.get_valid_project_name()
         project_path = Path(project_name)
         if project_path.exists():