Suggested test: copilot/close-older-issues-same-run-isolation

## Motivation

Link to the gh-aw PR: github/gh-aw#47585 — fix: prevent close-older-issues from closing issues created in the same run

When `close_older_issues: true` is set, a workflow that creates multiple issues in one run was inadvertently closing earlier issues from the same run (only the issue's own number was excluded from the close-search, not all issues created earlier in the same run).

## Proposed test

- **Workflow file**: `test-copilot-close-older-issues-same-run.md`
- **Trigger**: `workflow_dispatch`
- **Engine**: copilot
- **Safe output**: `create-issue` (×2, with `close_older_issues: true`)
- **Variant**: standard

## Minimal test prompt sketch

Instruct the agent to create two issues titled "Same-run isolation test A" and "Same-run isolation test B", both with `close_older_issues: true`. After the run completes, verify that both issues remain open — i.e. that the second `create-issue` did not close the first one created in the same run.

## New fixtures or secrets needed

None. Uses existing `githubnext/gh-aw-test` repo.

## Notes

Regression test for the fix in github/gh-aw#47585. Without the fix, the first issue created in the run would be closed by the second `create-issue` call because the per-call exclusion list only contained the newly-created issue's own number. The harness `e2e.sh` already knows how to verify that issues are open/closed post-run.

> Generated by [🔍 Suggest New E2E Tests](https://github.com/githubnext/gh-aw-test/actions/runs/30081887837) · sonnet46 20.1 AIC · ⌖ 5.75 AIC · ⊞ 6.1K · [◷](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 workflow file test-copilot-close-older-issues-same-run.md and inspect e2e.sh to see how it verifies issue state. Run the workflow_dispatch test using two create-issue steps with close_older_issues enabled. Done means both "Same-run isolation test A" and "Same-run isolation test B" remain open after the run.

Written by the indexing model from the issue text.