Error getting GitHub context fetch failed HttpError: fetch failed

**Describe the bug**
The GitHub Actions extension is reporting this error message:


In the Output window the following messages are shown:
```
Error getting GitHub context
fetch failed
HttpError: fetch failed
at c:\Users\xxx\.vscode\extensions\github.vscode-github-actions-0.26.2\dist\extension-node.js:2:1366802
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
at async c:\Users\xxx\.vscode\extensions\github.vscode-github-actions-0.26.2\dist\extension-node.js:2:1447997
at async Object.get (c:\Users\xxx\.vscode\extensions\github.vscode-github-actions-0.26.2\dist\extension-node.js:2:1447724)
at async Lt (c:\Users\xxx\.vscode\extensions\github.vscode-github-actions-0.26.2\dist\extension-node.js:2:1447916)
at async c:\Users\xxx\.vscode\extensions\github.vscode-github-actions-0.26.2\dist\extension-node.js:2:1626346
at async i.h (c:\Users\xxx\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:125:139661)

Cannot fetch github context
Error: Cannot fetch github context
at vt (c:\Users\xxx\.vscode\extensions\github.vscode-github-actions-0.26.2\dist\extension-node.js:2:1444927)
at async c:\Users\xxx\.vscode\extensions\github.vscode-github-actions-0.26.2\dist\extension-node.js:2:1626446
at async i.h (c:\Users\xxx\AppData\Local\Programs\Microsoft VS Code\resources\app\out\vs\workbench\api\node\extensionHostProcess.js:125:139661)

```

**To Reproduce**
Steps to reproduce the behavior:
1. Open VSCode. See GitHub Actions Output
2. Click refresh button on extension. Same error is logged

**Expected behavior**
No error message is shown

**Screenshots**
See above.

**Extension Version**
`0.26.2`

**Additional context**
I have seen issues https://github.com/github/vscode-github-actions/issues/77 and https://github.com/github/vscode-github-actions/issues/251.

I followed the instructions at https://github.com/github/vscode-github-actions/issues/77#issuecomment-1503960028 but the problem is still unresolved.

Reproduce the failure by opening VS Code and refreshing the GitHub Actions extension, then inspect the GitHub context fetch errors in the Output window. Compare the behavior with issues #77 and #251; done means the reported fetch failure no longer appears for the affected extension version.

索引モデルが issue の本文から書いたものです。