false positive error on `secrets` context access in forks

For a workflow that accesses secrets:

```yml
- name: "publish npm"
uses: "./.github/actions/publish-npm"
env:
NPM_TOKEN: "${{ secrets.NPM_TOKEN }}"
```

The extension is very helpful in checking if the secret `NPM_TOKEN` is actually defined or not.
However, it only checks secrets defined in the same repository (I suspect `origin` remote), and reports a false-positive error if it was defined in `upstream`, and `origin` is actually pointing to a fork:

> Context access might be invalid: NPM_TOKEN

**Expected behavior**

All remotes to be checked for secrets, not just `origin`, and the error is no longer reported.

**Screenshots**

**Extension Version**
`v0.26.3`

首先定位 extension 對 GitHub Actions secrets 的驗證邏輯，以及它如何判斷要檢查的 repository 或 remotes。重現 issue 中描述的 fork 和 upstream 情境，然後確認在 upstream 中定義的 secret 不再產生誤報的 context-access 錯誤。

由索引模型根據 Issue 內容生成。