Prepare v1.2.0

[ntavelis]

Prepare v1.2.0

Changes

• Add PHP 8.5 to CI matrix (unit and functional tests)
• Bump lcobucci/jwt from ^4.1.5 to ^4.3
• Bump nyholm/psr7 from ^1.4.1 to ^1.8
• Bump phpstan/phpstan from ^0.12.23 to ^1.0
• Bump phpunit/phpunit from ^8.0 to ^9.0
• Bump symfony/http-client from ^5.3 to ^6.0
• Fix missing declare(strict_types=1) in TokenProviderInterface
• Initialize $topics property to empty array in NotificationBuilder

Notes

No breaking changes to the public API. Minimum versions of some
dependencies have been raised, so consumers may need to update their own
dependency constraints.