feat(requests-ca): respect REQUESTS_CA_BUNDLE environment variable

Current implementation of `HttpClient` uses requests library to create a `PreparedRequest` and send it, but do not take into consideration the environment variables that `requests` do. This make it impossible to use custom CA certificates together with Airbyte. This PR adds the support of env settings to `HttpClient`.

The implementation is doing what `requests` library recommends when working with `PreparedRequests` to properly handle self-signed certificates: https://requests.readthedocs.io/en/latest/user/advanced/#prepared-requests

Author: bosper351

airbyte_cdk/sources/streams/http/http_client.py

@@ -545,6 +545,9 @@ def send_request(
             data=data,
         )
 
+        env_settings = self._session.merge_environment_settings(request.url, None, None, None, None)
+        request_kwargs = {**request_kwargs, **env_settings}
+
         response: requests.Response = self._send_with_retry(
             request=request,
             request_kwargs=request_kwargs,

unit_tests/sources/streams/http/test_http_client.py

@@ -1,6 +1,7 @@
 # Copyright (c) 2024 Airbyte, Inc., all rights reserved.
 
 import logging
+import os
 from datetime import timedelta
 from unittest.mock import MagicMock, patch
 
@@ -744,3 +745,23 @@ def test_given_different_headers_then_response_is_not_cached(requests_mock):
     )
 
     assert second_response.json()["test"] == "second response"
+
+@patch.dict("os.environ", {"REQUESTS_CA_BUNDLE": "/path/to/ca-bundle.crt"})
+def test_send_request_respects_environment_variables():
+    """Test that send_request respects REQUESTS_CA_BUNDLE environment variable."""
+    http_client = HttpClient(
+        name="test",
+        logger=MagicMock(),
+    )
+
+    with patch.object(http_client, '_send_with_retry') as mock_send_with_retry:
+        http_client.send_request(
+            http_method="GET",
+            url="https://api.example.com",
+            request_kwargs={"timeout": 10}
+        )
+        
+        passed_kwargs = mock_send_with_retry.call_args[1]["request_kwargs"]
+        
+        assert "verify" in passed_kwargs
+        assert passed_kwargs["verify"] == "/path/to/ca-bundle.crt"