HTTP HMAC PHP v6.2.0

What's Changed

• PHP 8.4 compatibility. by @japerry, @bserem in #72
• Update internal testing suite compatibility to PHPunit 9.6 and PHP 7.4+ by @japerry in #73
• Update tests by @japerry in #74

Upgrade notes

• The minimum supported PHP version is now 7.4 (previously 7.3). Runtime requirements are otherwise unchanged — psr/http-message still accepts ^1.0 || ^2.0.
• All implicitly nullable parameters now carry explicit ?Type hints, silencing the PHP 8.4 deprecation. This is source-compatible for callers, but if you extend AuthorizationHeaderBuilder, RequestSigner, ResponseSigner, HmacToken, HmacAuthenticationEntryPoint or the Malformed*Exception classes, mirror the explicit nullable types in your overrides to stay deprecation-free on 8.4.
• Suggested and development dependencies moved forward: Guzzle ^7.0, laminas-diactoros ^2.2 || ^3.0, symfony/security-bundle ^5.4, symfony/psr-http-message-bridge ^2.1 || ^6.4 || ^7.0, PHPUnit ^9.6.
• CI moved off Travis CI and the legacy ORCA workflow to GitHub Actions, testing PHP 7.4, 8.4 and 8.5.

Thanks

Special thanks to @bserem (Bill Seremetis) for the PHP 8.4 deprecation work in #69. That PR was not the one merged — #72 landed instead — but it independently identified the same set of fixes and helped get 8.4 compatibility over the line.

Full Changelog: 6.1.2...6.2.0