Improve GitHub Actions Stability and Error Reporting

[ ] 👍 Sweep Did Well
[ ] 👎 Sweep Needs Improvement I created this PR to fix the failing GitHub Actions.## Description This PR aims to improve the stability of our GitHub Actions workflows and enhance error reporting for easier diagnosis of failures. Given the recent issues with GitHub Actions runs failing without clear error logs, these changes are designed to provide more detailed feedback during failures and improve the robustness of our CI/CD processes.

The changes include:

A new GitHub Actions workflow that focuses on diagnostics and error reporting. This workflow runs the test suite and includes additional steps for logging and diagnostics.
Improved error handling and logging in cli.py, specifically in the sections where subprocesses are called to check git configuration and GitHub access token validity.
Enhanced test utilities in autogpts/autogpt/tests/utils.py for better error reporting in test environments, especially under CI conditions.

Summary of Changes

Created a new GitHub Actions workflow file .github/workflows/diagnostics.yml that includes steps for better error reporting.
Modified cli.py to improve error handling and logging during the setup process. Added more descriptive error messages and ensured that stderr is captured and logged in case of errors.
Enhanced the test utilities in autogpts/autogpt/tests/utils.py by implementing a function that can be used as a decorator or context manager for tests, capturing exceptions and logging them with detailed stack traces and any relevant test data.

These changes should help us better understand the root cause of any future GitHub Actions failures and make our CI/CD processes more robust.