build(deps): bump ffigen from 19.1.0 to 20.0.0 (#140)

Bumps [ffigen](https://github.com/dart-lang/native/tree/main/pkgs) from 19.1.0 to 20.0.0.
- [Release notes](https://github.com/dart-lang/native/releases)
- [Commits](https://github.com/dart-lang/native/commits/ffigen-v20.0.0/pkgs)

---
updated-dependencies:
- dependency-name: ffigen
  dependency-version: 20.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pubspec.yaml

@@ -83,7 +83,7 @@ dev_dependencies:
   riverpod_generator: ^3.0.3
   custom_lint: ^0.8.0
   riverpod_lint: ^3.0.3
-  ffigen: ^19.1.0
+  ffigen: ^20.0.0
   sct_dev_tools:
     path: ./packages/sct_dev_tools