Upgrade gh-aw to v0.79.8 and isolate agentic workflows into copilot-pat-pool environment

[jeffhandley]

• Update PAT Pool workflow to require an environment input
• Update PAT Pool README
• Update PAT Pool comments and template in all workflows
• Remove copilot-echo workflow that is no longer needed

[Copilot]

Pull request overview

This PR updates the repo’s gh-aw (Agentic Workflows) setup to the newer v0.79.8-generated lockfiles and moves agentic workflows onto an isolated copilot-pat-pool environment, while updating the PAT pool import/docs and removing the legacy copilot-echo workflow.

Changes:

• Upgrade generated .lock.yml workflows to gh-aw v0.79.8 output and associated action/container pins.
• Require agentic workflows to run under the copilot-pat-pool environment and pass an explicit environment input into the shared pat_pool.md import.
• Update PAT pool documentation and remove the no-longer-needed copilot-echo workflow + lockfile.

Reviewed changes

Copilot reviewed 16 out of 18 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
.github/workflows/validate-pat-pool.yml	Adds copilot-pat-pool environment to the validation job and updates the gh-aw setup action pin.
.github/workflows/shared/pat_pool.README.md	Documents the new environment-based PAT pool setup and updated import usage.
.github/workflows/shared/pat_pool.md	Makes environment a required import input and applies it to the pat_pool job.
.github/workflows/README.md	Updates guidance for skipping workflows in forks via github.event.repository.fork.
.github/workflows/copilot-echo.md	Removes the obsolete echo harness workflow.
.github/workflows/copilot-echo.lock.yml	Removes the generated lockfile for the obsolete echo workflow.
.github/workflows/code-review.md	Updates PAT pool import to pass environment and runs in copilot-pat-pool.
.github/workflows/code-review.lock.yml	Regenerated by gh-aw v0.79.8; incorporates environment isolation and new runtime/guardrail logic.
.github/workflows/ci-failure-scan.md	Updates PAT pool import and environment isolation for the scanner workflow.
.github/workflows/ci-failure-scan-feedback.md	Updates PAT pool import/environment and adjusts safe-output config fields.
.github/workflows/ci-failure-fix.md	Updates PAT pool import and environment isolation for the fixer workflow.
.github/workflows/breaking-change-doc.md	Updates PAT pool import and environment isolation for breaking-change-doc generation.
.github/dependabot.yml	Adjusts ignore rules for github/gh-aw-actions dependencies managed by gh-aw compilation.
.github/aw/actions-lock.json	Updates action lock entries for gh-aw v0.79.8 (including setup-cli).