Use Dart native build hooks for packaging

[jonasfj]

While native hooks in the Dart and Flutter SDK are still experimental, we should explore using them for building.

This would allow this package to no longer be a Flutter plugin, and thus, enable server applications using the Dart SDK to rely on this package.

[emersion]

Build hooks are now stable: https://dart.dev/tools/hooks

[koji-1009]

Hello!
I've created a project that simply wraps BoringSSL using Dart Hooks. What do you think of this approach?

https://github.com/koji-1009/boringssl_dart

[koji-1009]

I've created a PoC that separates the BoringSSL wrapper into a standalone package (boringssl_dart) using Dart Hooks.

• Repository: https://github.com/koji-1009/boringssl_dart
• Integration PR: PoC: Introducing Dart Hooks and Splitting Packages koji-1009/webcrypto.dart#13
• CI results: https://github.com/koji-1009/webcrypto.dart/actions/runs/22354673786

Native tests pass on Linux, macOS, Windows, iOS, and Android. Browser tests are unaffected by this change.

This approach keeps the BoringSSL build logic separate from webcrypto.dart, which simplifies the hooks adoption. Hope this is helpful as a reference.

[mark-dropbear]

I just wanted to say that I've run into really wanting to use this package (and not having a particularly suitable alternative to move to instead) in a server side context 3 times in the past 2 months across different projects now. I saw @HamdaanAliQuatil was working on a PR but it seemed stalled.

Hopefully you have some free cycles in the not too distant future to take a look at this again :)