build: (deps): bump matrix from 6.2.0 to 7.0.0

Bumps [matrix](https://github.com/famedly/matrix-dart-sdk) from 6.2.0 to 7.0.0.
- [Release notes](https://github.com/famedly/matrix-dart-sdk/releases)
- [Changelog](https://github.com/famedly/matrix-dart-sdk/blob/main/CHANGELOG.md)
- [Commits](https://github.com/famedly/matrix-dart-sdk/compare/v6.2.0...v7.0.0)

---
updated-dependencies:
- dependency-name: matrix
  dependency-version: 7.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

lib/pages/chat/chat.dart

@@ -1155,7 +1155,7 @@ class ChatController extends State<ChatPageWithRoom>
           true,
           false,
         );
-        users.sort((a, b) => a.powerLevel.compareTo(b.powerLevel));
+        users.sort((a, b) => a.powerLevel.level.compareTo(b.powerLevel.level));
         final via = users
             .map((user) => user.id.domain)
             .whereType<String>()