[workshop-sync] workshop/06-install-gh-aw.md: stale example version number in install output

## Workshop file reviewed
`workshop/06-install-gh-aw.md`

## Problem
The example install output shows a stale version number:
> You should see output like `gh-aw version 0.81.6`.

The latest gh-aw release is `v0.88.7` (published 2026-09-08), and the parallel side-quest file `side-quest-06-04-install-local.md` already uses a newer example (`gh-aw version 0.88.2`) for the same install step, making this file inconsistent with its sibling doc and out of date with the current release.

## Current correct behavior
Learners installing today will see a version close to `0.88.x`, not `0.81.6`. The example output should track a version reasonably close to the current release so it doesn't look wrong or alarming to learners who see a much higher version number after installing.

## Suggested fix
Update line 44 of `workshop/06-install-gh-aw.md` from:
```
You should see output like `gh-aw version 0.81.6`.
```
to something like:
```
You should see output like `gh-aw version 0.88.x` (the exact patch version will vary).
```
This aligns the example with the current release (`v0.88.7`) and with `side-quest-06-04-install-local.md`.

> [!WARNING]
>
> Firewall blocked 2 domains
>
> The following domains were blocked by the firewall during workflow execution:
>
> - `githubnext.github.io`
> - `pypi.org`
>
> To allow these domains, add them to the `network.allowed` list in your workflow frontmatter:
>
> ```yaml
> network:
> allowed:
> - defaults
> - "githubnext.github.io"
> - "pypi.org"
> ```
>
> See [Network Configuration](https://github.github.com/gh-aw/reference/network/) for more information.
>
>

> Generated by [🔍 Workshop Sync Check](https://github.com/githubnext/gh-aw-workshop/actions/runs/35056821515) · copilot · auto · 142.2 AIC · ⌖ 5.41 AIC · ⊞ 8.6K · [◷](https://github.com/search?q=repo%3Agithubnext%2Fgh-aw-workshop+is%3Aissue+%22gh-aw-workflow-call-id%3A+githubnext%2Fgh-aw-workshop%2Fworkshop-sync-check%22&type=issues)
> - [x] expires on Sep 17, 2026, 4:54 AM UTC

Open workshop/06-install-gh-aw.md and inspect line 44, then compare the install example with side-quest-06-04-install-local.md and the current release noted in the issue. Update the stale version wording so it is close to the current 0.88.x release and explains that the exact patch version may vary; done when the workshop and sibling examples are consistent.

Written by the indexing model from the issue text.