2.0.0-beta15

What's Changed

• Update Bref v2 Lambda layers 2.0.0-beta12 by @github-actions in #1428
• Move final to an annotation so that event classes can be mocked in tests by @mnapoli in #1430
• Allow setting runtime: php-xx in provider.runtime by @mnapoli in #1432

Full Changelog: 2.0.0-beta14...2.0.0-beta15