Pinned workflows for folders other than the first in a Code Workspace don't appear in the status bar

**Describe the bug**
Clicking the pin & unpin buttons on workflows in a multi-project workspace add `PROJECT-FOLDER-NAME/.github/workflows/WORKFLOW-NAME.yml` to `"github-actions.workflows.pinned.workflows"`, but in actuality, the only workflows that can actually show in the status bar are workflows for the first project in the workspace, and only when *not* qualified with the `PROJECT-FOLDER-NAME`

**To Reproduce**
Steps to reproduce the behavior:
1. Open a new VSCode window and click File > Add Folder to Workspace, then choose a GitHub project with `.github/workflows`. Do it again for another GitHub project with workflows.
2. In the GitHub Actions extension workflows list, pin workflows from both projects.
3. No workflows will appear in the status bar.
4. Open Workspace Settings (JSON), and for a workflow from the first project folder listed, remove the project name. IE, the path should be `.github/workflows/WORKFLOW-NAME.yml`.
5. The workflow will appear in the status bar.

**Expected behavior**
Pinned workflows in a multi-project workspace should appear when they're qualified with the project name. The path `.github/workflows/*` in a multi-project workspace probably shouldn't resolve to anything and therefore should do nothing.

**Extension Version**
`v0.27.0`

Reproduce the issue in a multi-project Code Workspace using the GitHub Actions extension, then trace how pinned workflow paths are stored and resolved for the status bar. Done means qualified workflows from each project appear, while an unqualified `.github/workflows/*` path does nothing in a multi-project workspace.

索引モデルが issue の本文から書いたものです。