- Removed the option to not specify any service account and therefore go to a fallback path, to ensure compatibility with ESM
- Improved documentation for creating FCM objects with CommonJS and ESM
- Added support for Deno
- Used new interface for building JWT client

Updated dependencies:
googleapis -> 156.0.0
@types/async -> 3.2.25
@types/node -> 24.3.0
typescript -> 5.9.2