Add GITHUB_TOKEN for shivammathur/setup-php@v2 to avoid being rate limited

[glensc]

• https://github.com/perftools/xhgui/actions/runs/3831619059/jobs/6520959321

==> Setup Tools
✓ composer Added composer 2.5.1
✗ php-cs-fixer 403: rate limit exceeded
✓ cs2pr Added cs2pr 1.8.3

Docs:

• https://github.com/shivammathur/setup-php/blob/8e2ac35f639d3e794c1da1f28999385ab6fdf0fc/README.md#wrench-tools-support