⬆️ Bump weak_map from 3.0.1 to 4.0.0 (#24)

Bumps [weak_map](https://github.com/marcglasberg/weak_map) from 3.0.1 to 4.0.0.
- [Changelog](https://github.com/marcglasberg/weak_map/blob/master/CHANGELOG.md)
- [Commits](https://github.com/marcglasberg/weak_map/commits)

---
updated-dependencies:
- dependency-name: weak_map
  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

@@ -13,7 +13,7 @@ dependencies:
   equatable: ^2.0.5
   meta: ^1.9.1
   recursive_regex: ^1.0.0
-  weak_map: ^3.0.1
+  weak_map: ">=3.0.1 <5.0.0"
 
 dev_dependencies:
   cli_script: ^1.0.0