json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0) in DAP feature test
## Problem
`rspec-ee system pg duo_workflow_service` job is flaky due to the following error:
```
[error ] Expecting value: line 1 column 1 (char 0) [exceptions] additional_details={'context': 'JSON decode error', 'response_type': <class 'str'>, 'content': "''"} correlation_id=01KMK3PTY2JZB8ZFS90A5YVFSV exception_class=JSONDecodeError gitlab_global_user_id='W5WH3w+JxAEl+P0+I6pcSpJeVNA/1Kk2W3bhgcpTfY0=' status_code=None workflow_id=2
Stack (most recent call last):
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/.venv/bin/duo-workflow-service", line 6, in <module>
sys.exit(run_bootstrap())
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/bootstrap.py", line 20, in run_bootstrap
run_app()
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/server.py", line 987, in run_app
run(get_config())
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/server.py", line 983, in run
asyncio.get_event_loop().run_until_complete(serve(config, port))
File "/usr/local/python-3.12.12/lib/python3.12/asyncio/base_events.py", line 678, in run_until_complete
self.run_forever()
File "/usr/local/python-3.12.12/lib/python3.12/asyncio/base_events.py", line 645, in run_forever
self._run_once()
File "/usr/local/python-3.12.12/lib/python3.12/asyncio/base_events.py", line 1999, in _run_once
handle._run()
File "/usr/local/python-3.12.12/lib/python3.12/asyncio/events.py", line 88, in _run
self._context.run(self._callback, *self._args)
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/.venv/lib/python3.12/site-packages/langgraph/pregel/_loop.py", line 1212, in _checkpointer_put_after_previous
await cast(BaseCheckpointSaver, self.checkpointer).aput(
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/checkpointer/gitlab_workflow.py", line 752, in aput
response = await self._client.apost(
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/gitlab/http_client.py", line 67, in apost
return await self._call(
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/gitlab/executor_http_client.py", line 45, in _call
body = self._parse_response(
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/gitlab/http_client.py", line 131, in _parse_response
log_exception(
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/tracking/errors.py", line 27, in log_exception
log.error(
===============================================================================
Traceback (most recent call last):
File "/builds/gitlab-org/gitlab/tmp/tests/gitlab-ai-gateway/duo_workflow_service/gitlab/http_client.py", line 125, in _parse_response
return json.loads(response)
^^^^^^^^^^^^^^^^^^^^
File "/usr/local/python-3.12.12/lib/python3.12/json/__init__.py", line 346, in loads
return _default_decoder.decode(s)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/python-3.12.12/lib/python3.12/json/decoder.py", line 338, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/python-3.12.12/lib/python3.12/json/decoder.py", line 356, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
```
https://gitlab.com/gitlab-org/quality/analytics/team/-/work_items/595#note_3211326204
[example job](https://gitlab.com/gitlab-org/gitlab/-/jobs/13648580419)
## Proposal
Fix the root cause
issue