Suggested test: copilot/mcp-issue-dependency-tools

## Motivation

Link to the gh-aw PR: github/gh-aw#45082 — Update GitHub MCP toolsets mapping: add `issue_dependency_read` and `issue_dependency_write` to the `issues` toolset.

## Proposed test

- **Workflow file**: `test-copilot-mcp-issue-dependency-tools.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `add-comment`
- **Variant**: standard

## Minimal test prompt sketch

Ask the agent to use the GitHub MCP server to read the dependencies of a specific issue in `githubnext/gh-aw-test` (using `issue_dependency_read`), then post an `add-comment` safe output with the dependency count. This exercises that `issue_dependency_read` is correctly registered under the `issues` toolset and accessible via the MCP gateway.

## New fixtures or secrets needed

None — `githubnext/gh-aw-test` supports issue dependencies natively. A long-lived issue with known dependencies could serve as the fixture, or the test can use `issue_dependency_read` on any issue and assert a non-error response.

## Notes

The existing `test-copilot-mcp.md` tests general MCP access but does not exercise issue-dependency tools specifically. `test-copilot-link-sub-issue.md` covers sub-issues, not dependency read/write. Adding this test closes the regression gap introduced by PR #45082.

> [!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/29240055947) · 24.4 AIC · ⌖ 5.53 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 with the proposed test file, test-copilot-mcp-issue-dependency-tools.md, and compare its structure with test-copilot-mcp.md and test-copilot-link-sub-issue.md. Run it through workflow_dispatch using the copilot engine. Done means the agent reads issue dependencies through issue_dependency_read and posts an add-comment safe output containing the dependency count without an MCP error.

Written by the indexing model from the issue text.