fix: Add missing os import in provider files

Co-Authored-By: Joe Moura <joao@crewai.com>

src/crewai/cli/provider.py

@@ -1,4 +1,5 @@
 import json
+import os
 import time
 from collections import defaultdict
 from pathlib import Path

tests/cli/provider_test.py

@@ -1,4 +1,5 @@
 import json
+import os
 import pytest
 import requests
 import time