Suggested test: copilot/sparse-checkout-symlink-agents

## Motivation

Link to the gh-aw PR: github/gh-aw#43909 — _fix: follow symlinks when generating sparse checkout for .github subdirs_

When `.github/agents` (or `.github/skills`/`.github/prompts`) is a git symlink pointing to a directory outside `.github/` (e.g. `../.ai/agents`), the compiler-generated sparse checkout previously only fetched the symlink blob, leaving a dangling symlink at runtime and breaking any `{{#runtime-import .github/agents/.md}}` expression. The fix resolves symlinks and appends the real target path to `extraPaths`.

## Proposed test

- **Workflow file**: `test-copilot-sparse-checkout-symlink-agents.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `create-issue`
- **Variant**: standard (or `siderepo` — see Notes)

## Minimal test prompt sketch

A workflow that imports an agent file reachable only through a symlinked `.github/agents` directory. If the sparse checkout does not follow the symlink, the runtime-import fails and the run errors before the agent can create the issue. A successful issue creation confirms the fix is working.

## New fixtures or secrets needed

**New fixture required**: The test repository (or `githubnext/gh-aw-side-repo`) needs a `.github/agents` symlink pointing to a directory outside `.github/`, with at least one `.md` agent file at the target location. This is the primary open question before this test can be written.

## Notes

This may be best implemented as a `siderepo` variant to keep the fixture change isolated to `githubnext/gh-aw-side-repo`. Alternatively, the symlink could be added to `githubnext/gh-aw-test` itself. Needs fixture setup before the `.md` source can be written — hence an issue rather than a PR.

> [!WARNING]
>
> Firewall blocked 1 domain
>
> The following domain was blocked by the firewall during workflow execution:
>
> - `awmgmcpg`
>> To allow these domains, add them to the `network.allowed` list in your workflow frontmatter:
>
> ```yaml
> network:
> allowed:
> - defaults
> - "awmgmcpg"
> ```
>
> See [Network Configuration](https://github.github.com/gh-aw/reference/network/) for more information.
>
>

> Generated by [🔍 Suggest New E2E Tests](https://github.com/githubnext/gh-aw-test/actions/runs/28856843748) · 41 AIC · ⌖ 6.66 AIC · ⊞ 5.6K · [◷](https://github.com/search?q=repo%3Agithubnext%2Fgh-aw-test+is%3Aissue+%22gh-aw-workflow-call-id%3A+githubnext%2Fgh-aw-test%2Fsuggest-new-e2e-tests%22&type=issues)

Start by inspecting the existing copilot sparse-checkout tests and the proposed test-copilot-sparse-checkout-symlink-agents.md workflow. Then determine whether the fixture belongs in githubnext/gh-aw-side-repo or githubnext/gh-aw-test, including the .github/agents symlink and target agent file. Done means the workflow_dispatch run succeeds and creates an issue through the runtime-imported agent.

Written by the indexing model from the issue text.