Prepare v2.1.0 release

[reinder83]

Summary

• prepare tests to run in parallel to keep CI efficient
• switch the default preset to the per profile and re-run pint formatting while avoiding newlines between constants
• plan for a future 3.0.0 release with breaking mask changes and document it in README/release notes before publishing
• add Enum based flags

[Copilot]

Pull request overview

This PR modernizes the project’s test/tooling setup by migrating the existing PHPUnit-style test class to Pest, introducing baseline Rector configuration, and updating PHPUnit configuration to align with newer PHPUnit versions.

Changes:

• Add Pest bootstrap (tests/Pest.php) and convert BinaryFlagsTest from a PHPUnit\Framework\TestCase class to Pest tests.
• Add a rector.php configuration for applying Rector to src/ and tests/.
• Update phpunit.xml for PHPUnit 10-style configuration and adjust composer.json dev tooling dependencies (Pest/Pint/Rector) and PHP version constraints.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/Pest.php	Adds Pest bootstrap configuration for the test suite.
tests/BinaryFlagsTest.php	Migrates the test suite from PHPUnit class methods to Pest DSL tests.
rector.php	Introduces Rector config targeting src/ and tests/.
phpunit.xml	Updates PHPUnit configuration to the PHPUnit 10 schema and <source> layout.
composer.json	Updates dev dependencies and changes minimum PHP/platform configuration.

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[Copilot]

Pull request overview

Copilot reviewed 35 out of 36 changed files in this pull request and generated 3 comments.

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[Copilot]

Pull request overview

Copilot reviewed 35 out of 36 changed files in this pull request and generated 3 comments.

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