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_details/chat_details_view.dart

@@ -44,7 +44,7 @@ class ChatDetailsView extends StatelessWidget {
       ),
       builder: (context, snapshot) {
         var members = room.getParticipants().toList()
-          ..sort((b, a) => a.powerLevel.compareTo(b.powerLevel));
+          ..sort((b, a) => a.powerLevel.level.compareTo(b.powerLevel.level));
         members = members.take(10).toList();
         final actualMembersCount =
             (room.summary.mInvitedMemberCount ?? 0) +