Release version with PHP 8.5 support

[emyller]

💡 Feature / Idea

Publish a new release with PHP 8.5 support. The main branch already includes the updated constraint (8.1 - 8.5), but the current stable release (0.10.0) only supports PHP 8.1–8.4.

Have you spent some time to check if this issue has been raised before?

• [x] I have read googled for a similar issue or checked our older issues for a similar idea

Have you read the Code of Conduct?

• [x] I have read the Code of Conduct

Pitch

PHP 8.5.0 was released on November 20, 2025. Downstream projects depending on this library cannot support PHP 8.5 until a new version is published.

For example, Flagsmith PHP SDK 5.0.0 cannot be installed on PHP 8.5 due to this constraint. See Flagsmith/flagsmith-php-client#127.