Use reactphp/async instead of clue/reactphp-block

[clue]

See https://github.com/reactphp/async
Refs clue/reactphp-block#68 and clue/reactphp-block#67 and reactphp/async#65
Builds on top of #79 and #70

[Copilot]

Pull request overview

This PR migrates the test suite from using the deprecated clue/reactphp-block library to the modern reactphp/async library. The migration simplifies blocking operations in tests by using fibers-based async/await instead of the old blocking wait mechanism.

Changes:

• Replaced clue/block-react dependency with reactphp/async in composer.json
• Updated FunctionalTest.php to use React\Async\await() instead of Block\await()
• Updated README.md documentation to reference reactphp/async instead of clue/reactphp-block

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
composer.json	Replaced clue/block-react with react/async in dev dependencies
tests/FunctionalTest.php	Migrated from Block\await to React\Async\await, removed loop initialization, updated imports
README.md	Updated blocking code example to use reactphp/async instead of clue/reactphp-block

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

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