Fix SSL certificate verification in provider data fetching

- Add get_ssl_verify_config() function to respect SSL environment variables
- Support REQUESTS_CA_BUNDLE, SSL_CERT_FILE, CURL_CA_BUNDLE env vars
- Fallback to certifi.where() when no custom CA bundle is specified
- Improve error handling for SSL verification failures
- Add comprehensive tests for SSL configuration scenarios

Fixes #2978

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

tests/cli/test_constants.py

@@ -1,6 +1,6 @@
 import pytest
 
-from crewai.cli.constants import ENV_VARS, MODELS, PROVIDERS
+from crewai.cli.constants import ENV_VARS, JSON_URL, MODELS, PROVIDERS
 
 
 def test_huggingface_in_providers():
@@ -21,3 +21,9 @@ def test_huggingface_models():
     """Test that Huggingface models are properly configured."""
     assert "huggingface" in MODELS
     assert len(MODELS["huggingface"]) > 0
+
+
+def test_json_url_is_https():
+    """Test that JSON_URL uses HTTPS for secure connection."""
+    assert JSON_URL.startswith("https://")
+    assert "raw.githubusercontent.com" in JSON_URL