Update layers (updated PHP versions + new PHP 8 layers)

Merge pull request brefphp#674 from brefphp/ping

Add very basic analytics via a ping

Covers brefphp#670 with a test

Merge pull request brefphp#604 from victormacko/handle-v2-payload

Support for HTTP API brefphp#602

Update layers

Merge pull request brefphp#635 from brefphp/laravel-docs

Continue to improve the Laravel documentation

Upgrade PHPUnit

Update download script for PHP sources so that the Docker build fails…

… less often

Merge pull request brefphp#618 from brefphp/fix-missing-dependency

Fix missing dependency for PSR-15 handlers

Typo